RU2380834C1 - Method for laser space communications and facility for its implementation - Google Patents

Abstract

FIELD: information technologies.

SUBSTANCE: invention refers to the area of laser space communications and laser equipment and is intended for creation of fixed laser space communications facilities in adjacent space - before orbit of the Moon, and in far space on route form the Earth to Mars, and throughout solar system. Following operations are executed: determination of laser radiation Doppler frequency shift from base part of laser space communications facility when it is received in board facility part; shifting laser radiation optical frequency in base part of facility by negative value of measured Doppler shift; applying quantum amplification of laser radiation and measuring shift of its optical frequency in board part of facility, as well as shift of receiving band central frequency and quantum amplification in board and base parts of facility; determination of quality parametres of established laser space communications; generation of laser radiation, receive and quantum amplification of laser communication signals with established shifts of optical frequencies.

EFFECT: increase in laser space communications range, increase volumes and rate of data transmission between space vehicles and ground stations throughout solar system.

11 cl, 12 dwg

Description

The invention relates to laser space communication systems and quantum electronics. The invention is intended for the organization of long-distance space communication lines between a spacecraft located in deep space and a space communication base station located on the surface of the Earth, or on a spacecraft in low Earth orbit.

Known methods for organizing laser space communication, similar to space radio communication systems, which include generating electromagnetic radiation of the optical wavelength range — laser radiation, modulating the radiation with an information signal, directing the laser radiation with an optical telescope toward a correspondent receiver, receiving laser radiation from an optical receiving antenna, registration and demodulation of laser radiation using a photo detector with sensitivity in the range wavelength corresponding to a wavelength of laser radiation the laser oscillator-transmitter [1]. The disadvantages of these open communication lines include the short-range range on cosmic scales, due to the limited sensitivity of direct photodetector detectors, as well as the low noise immunity of the photodetector due to the wide sensitivity band of the photodetectors used.

Known methods of laser communication, using for registration of received radiation methods of heterodyne reception (photo mixing) of signals of the optical wavelength range [2]. These heterodyne reception methods have a slightly higher sensitivity compared to direct photodetection methods of optical signals, but they have a number of significant drawbacks.

The disadvantages of this method of receiving optical information signals include, first of all, the presence of intrinsic noise of the laser local oscillator, which impede the realization of high sensitivity of the reception of optical (laser) information signals. Moreover, when implementing a system of long-distance space laser communication, characterized by a large value of the Doppler shift of the laser radiation frequency, direct reception of laser radiation by the heterodyne method is ineffective due to the shift of the intermediate frequency of the mixing signals at the output of the optical photodetector - optical frequency converter - to a region of very high frequencies of the order of units and tens of gigahertz, the amplification of which from the output of photodetectors at the level of the ultimate quantum sens pheno- impossible. Due to the limited sensitivity, these methods of laser space communication are characterized by a low range.

A known method of receiving and transmitting information by an optical signal [3], including the generation, modulation, emission and reception of laser signals, counting time intervals between optical pulses, determining the values of the current time intervals, subtracting the constant and determining the exact values between the current and previous optical pulses. The disadvantages of this method include the short range of the laser communication systems based on this method due to the inability to provide the ultimate quantum sensitivity when receiving optical pulses.

A known method of receiving and transmitting information by optical signals [4], including the reception of optical signals using photodetectors, signal delay through an optical delay line, combining and joint processing of optical signals. The disadvantages of this method include the low sensitivity of the used method of direct photodetection of optical signals and, accordingly, the short range of the communication system based on this method.

As a prototype, the method implemented according to the patent [5] was selected when performing laser space communication using laser communication terminals installed on the base station and on board the spacecraft (SC).

The method includes the generation and modulation of laser radiation in the base station and onboard the spacecraft, the mutual orientation (guidance) of the receiving and transmitting optical antennas, the reception of laser radiation, spatial analysis - filtering - received radiation - images of the observed field, separation and joint processing of the separated images, registration optical signals by direct photo detection methods. The disadvantages of this method and a laser-based space communication system based on it should be attributed to the small range of action on the cosmic scales, due to the relatively low sensitivity of direct photodetection methods of optical signals that do not allow the ultimate quantum sensitivity to be realized when organizing laser-space communication using this method. The range of the laser space communication system, as indicated in [5], is L = 40,000 km, which allows laser communication only in near space with spacecraft orbiting in near-Earth orbits. It should be noted that the information transfer rate indicated in [5] is achieved only within the specified range L. At distances greater than L, such information transfer speed is not realized. For space communication with a station on the moon and within the solar system, this method of constructing a laser communication is unsuitable. Another significant drawback of this method and space communication system is the low noise immunity, which makes it impossible to receive laser information signals under conditions of strong background illumination, for example, against the background of the solar disk or against the background of the radiation of the plasma surrounding the spacecraft when it lands on Earth and enters dense layers of the atmosphere .

As a prototype for a complex of laser space communications that implements the method of laser space communications, the laser communication device (terminal) according to the patent [5], which implements the prototype method, is selected.

The technical result achieved is the following: an increase in the range of the laser-space communication complex, an increase in the volume and speed of information transfer in laser-space communication systems between rapidly moving space objects, the realization of the ultimate quantum sensitivity when receiving broadband laser information signals in the conditions of long-distance space communication between moving objects - spacecraft (SC). The implementation of laser space communications when receiving laser signals against the background of solar radiation and the emission of brightly glowing space objects. Realization of continuous communication with the spacecraft (SC) at the time of its entry into the dense layers of the atmosphere and landing on Earth through the plasma layer surrounding the SC.

A new technical result is achieved as follows:

1. In the known method, which includes sequential generation and modulation of laser radiation in the base and onboard parts of the complex, the mutual orientation of the transmitting and receiving optical antennas and the mutual reception of laser radiation in the base and onboard parts of the complex, before the generation of laser radiation in the base of the complex, the speed of movement is determined the onboard part of the complex relative to the base part of the complex, determine the Doppler frequency shift Δf _{d of} laser radiation from the base part of the complex when it is received at the onboard hour of the complex, the generation of laser radiation in the base part of the complex is carried out with a shift of the optical frequency Δf ₁ by a negative value of the Doppler frequency shift Δf ₁ = -Δf _d , after receiving this laser radiation in the side part of the complex, its quantum gain is carried out, the shift of the optical frequency Δv _{2 is} measured received and amplified laser radiation relative to the reference optical frequency f ₀ , the generation of laser radiation in the side of the complex is carried out with a shift of the optical frequency Δf ₂ to negative the measured optical frequency shift Δν _{2 of the} received laser radiation Δf ₂ = -Δv ₂ , additionally modulate the laser radiation generated in the airborne part by the measured optical frequency shift Δν ₂ , the subsequent reception and quantum amplification of the laser radiation in the airborne part of the complex is performed with a central frequency shift f _p2 the reception band by the value measured shift Δν ₂ optical frequency of the laser radiation received after receiving laser radiation from the sides of the complex in the base of the second part of the complex, it is quantum amplified with a shift of the center frequency f _f1 of the reception band by the previously measured Doppler frequency shift Δf _d , the shift Δν _{1 of the} optical frequency of the received and amplified laser radiation in the base part of the complex relative to the reference optical frequency f ₀ , in the base part is measured complex demodulation is carried out by the bead portion of the received laser complex and receive information on the magnitude of the optical frequency shift Δν _2, previously measured in the bead portion komple sa, based on the obtained optical frequency shift Δν _1, Δν ₂ define the parameters of the laser space communication mode ε _1, ε _2, which judged as set laser space communications and if the conditions:

ε ₁ ≤0.01 and ε ₂ ≤0.01

decide on the establishment of a regular mode of laser space communication, in which the base and onboard parts of the complex generate laser radiation and receive and quantum amplify laser radiation with previously established optical frequency shifts of the generated laser radiation and with shifts of the central frequencies of the laser reception bands.

2. The parameters of the established laser space communications ε ₁ and ε _{2 are} determined on the basis of the following relationships:

where Δν ₁ and Δν ₂ are the shifts of the optical frequency, measured respectively in the base (Δν ₁ ) and on-board (Δν ₂ ) parts of the complex;

Δf _d is the magnitude of the Doppler shift of the optical frequency of the laser radiation, the determination of which is carried out in the base part of the complex.

3. If at least one of the conditions ε ₁ ≤0.01 and ε ₂ ≤0.01 is not fulfilled, the sum of the measured values Δν ₁ , Δν ₂ shifts of the optical frequency is used as the value of the Doppler shift of the optical frequency Δf _d :

4. The determination of the Doppler shift of the optical frequency Δf _{d of} laser radiation from the base of the complex when received in the onboard part of the complex is carried out in accordance with the formula:

where c is the speed of light, V ₁ is the speed of movement of the onboard part of the complex relative to the base part of the complex in the direction of the mutual sight line connecting the base and onboard parts of the complex; f ₀ is the optical frequency of the laser radiation generated in the base part of the complex and corresponding to the optical frequency of the working quantum transition of the active substance used in the generation of laser radiation and in the implementation of quantum amplification of laser radiation in the base and side parts of the complex.

5. As the reference optical frequency f _{0 of the} laser radiation, the optical frequency of the working quantum transition of the active substance used in the generation of laser radiation and quantum amplification of laser radiation in the base and side parts of the complex is adopted.

6. In the complex of laser space communications (LKS), consisting of identical base and airborne parts located on different spacecraft (SC), each of which contains a receiving and transmitting optical antenna mounted on the base element and rigidly connected to it, supporting a rotary device (OPU) kinematically connected to the base element, an optical filter, first and second photodetector blocks (FPB), a laser radiation modulator with a control unit, an information source block and an information receiver block, a control block of the complex, the control input of the control amplifier, the outputs of the first and second FPBs, the information receiving block and the information source block are connected to the complex control unit, the laser radiation modulator control unit is connected to the complex control unit, an active quantum filter with tuning is introduced into each of the identical parts of the complex frequency (AFCF), a frequency-tunable laser generator (LGPF), a multi-channel laser communication unit, the first and second optical frequency measurement units, a reference laser radiation generator, determination of motion parameters, the first and second lenses, three reflective mirrors and six translucent mirrors, while the optical input of the AFFC is connected to the optical output of the receiving optical antenna, the optical output of the AFFC is connected to the optical input of the first FPB through the optical filter, the first translucent mirror and the first lens, and with the optical input of the second FPB through the optical filter, the first and second translucent mirrors and the second lens, an additional optical output of the AFFC is connected to the optical inputs of the multichannel laser unit connection of the first optical frequency measurement unit through the optical filter and the first, second, third translucent mirrors and the first reflective mirror, the LGPH optical output is connected to the optical input of the transmitting optical antenna through a laser modulator and to the optical input of the second optical frequency measurement unit through the sixth translucent the mirror and the third reflective mirror, the optical output of the reference laser radiation generator is optically coupled to the second optical inputs of the second the optical frequency measuring unit, the first optical frequency measuring unit by means of the fourth and fifth translucent mirrors and the multi-channel laser communication unit through the fourth and fifth translucent mirrors and the second reflective mirror, while the control inputs of the AFFC and LGPCH are connected to the control unit, the inputs of which are connected to the first and to the second optical frequency determination units and to the multi-channel laser communication unit, the output of the motion parameter determination unit is connected to the control unit and to the output of the external target designation.

7. An active quantum filter with frequency tuning (AFFC) contains optically coupled input diaphragm, input translucent mirror, cuvette with transparent input and output windows and active substance and pump unit, optical plate with positioning unit, acousto-optic modulator with unit, sequentially mounted on the optical axis control, the output translucent mirror, a piezoelectric element with a control unit connected to the output translucent mirror, the control unit of the frequency of the spectral line, connected a cell with an active substance, while the control inputs of the pump unit, positioning unit, acousto-optic modulator control unit, piezoelectric element control unit and spectral line frequency control unit are connected to the complex control unit.

8. The frequency-tunable laser generator (LGPF) contains optically coupled output diaphragm, a translucent cavity mirror, a cell with an active substance, a pump unit, a control unit for the generation frequency connected to a cell with an active substance, an optical plate with a positioning unit , a reflector mirror of the resonator, while the control inputs of the pump unit, the control unit for the generation frequency and the positioning unit are connected to the control unit of the complex.

9. The multi-channel laser communication unit comprises a photodetector in series, a first intermediate-frequency amplifier, a radio frequency mixer with a local oscillator, a multi-channel intermediate-frequency amplifier, a multi-channel demodulator, and optically coupled optical attenuator and an acousto-optical modulator, while the input of the optical attenuator by means of a reflective mirror and an optical beam splitter connected to the optical input of the photodetector, and the input of the acousto-optical modulator is optically connected to the output nnogo generator of laser radiation by the reflective and semi-transparent mirrors, control the electrical input of the optical attenuator and the control input of the acousto-optic modulator connected to the output of a complex control unit, the multi-channel demodulator output is connected to an input of a complex control unit.

10. The active frequency tunable quantum filter (AFCF) is made on the basis of a fiber optic quantum amplifier containing an active optical fiber, the input of which is optically coupled to the input lens through the optical splitter and the first fiber optic Bragg grating, and the output of which through the second fiber the optical Bragg grating is optically coupled to the output lens, the second input of the optical splitter is connected to the semiconductor laser pumping unit, the first and second fiber-optic Braggs Gratings (FBGs) are connected to the parameter control unit.

11. Frequency tunable laser generator (LGPF) contains an active optical fiber, the input of which through the first fiber optic array is optically coupled to a semiconductor laser pumping unit, and the output is optically coupled through a second fiber optic array with an output lens, the first and second fiber optical gratings are connected to the parameter control unit.

12. An active frequency tunable quantum filter (AFCF) contains a semiconductor laser amplifier coupled to an optical fiber, the optical input of which is connected to the input and output lenses through an optical splitter and coupling elements, and the optical output is connected to an optical fiber Bragg grating connected to control unit parameters.

Figure 1 presents a diagram of the composition and figure 2 a diagram of the organization of communication of a complex of laser space communications (LKS) - hereinafter simply a complex - that implements the proposed method of laser space communications.

According to the proposed method, laser space communication is established between the base part of the complex and the airborne part of the complex. The basic part of the complex is the main one and is installed on the surface of the Earth or is located on a basic spacecraft (BSC), rotating in low Earth orbit. The onboard part of the complex is located on board the second spacecraft (KA2) located in deep space, for example, in the region of the planet Mars. The base and side parts of the complex have an identical composition.

Figure 1 presents a block diagram of the base (onboard) part of the complex, where the following elements are indicated:

1. The receiving optical antenna.

2. The basic element.

3. Slewing ring (OPU).

4. Transmitting optical antenna.

5. Active quantum filter with frequency tuning (AFFC).

6. Optical filter.

7. The first and second - pos.8 - lenses.

9. The first photodetector unit.

10. The second photodetector unit.

11. Block multi-channel laser communication.

12. The first unit for measuring the optical frequency.

13, 14, 15. The first, second and third translucent mirrors.

16. The first reflective mirror.

17. Reference laser generator.

18. The second reflective mirror.

19, 20. Fourth and fifth translucent mirrors.

21. Laser generator with frequency tuning (LGPCH).

22. The second unit for measuring the optical frequency.

23. Sixth translucent mirror.

24. Third reflective mirror.

25. The control unit of the complex.

26. Block for determining motion parameters.

27. The block is the recipient of information.

28. Block source of information.

29. External target designation unit (not included in the complex).

30. Laser modulator with control unit 31.

32. The platform of the spacecraft.

Figure 2 presents a diagram of the organization of laser space communication between the base and onboard parts of the complex that implements the method of laser space communication.

In figure 2, the following elements are indicated:

2-1. The base part of the complex.

2-2. The side of the complex.

2-3. Basic spacecraft (BKA) (carrier) or the surface of the Earth.

2-4. The second spacecraft carrying the onboard part of the complex.

2-5, 2-6. Transmitting and receiving optical antennas of the base part of the complex.

2-7, 2-8. Receiving and transmitting optical antennas of the onboard part of the complex.

2-9, 2-10. Blocks for determining motion parameters in the base and onboard parts of the complex.

2-11, 2-12. Slewing-rotary devices (OPU) in the base and onboard parts of the complex.

2-13, 2-14. Hardware units in the base and onboard parts of the complex.

2-15, 2-16. Bearing structures in the base and side parts of the complex (basic elements). The base of the complex can also be installed on the earth's surface.

Figure 3 shows a block diagram of a laser generator with frequency tuning (LGPCH), which contains the following elements:

3-1. Ditch with the active substance.

3-2. Pumping unit.

3-3. Generation frequency control unit.

3-4. Translucent and reflective 3-5 cavity mirrors.

3-6. Optical plate with positioning unit 3-7.

3-10. Output aperture.

Figure 4 shows a block diagram of an active quantum filter with frequency tuning (AFCF), which contains the following elements:

4-1. Ditch with transparent entrance and exit windows and active substance.

4-2. Pumping unit.

4-3. Spectral line frequency control unit.

4-4. Entrance translucent mirror.

4-5. Translucent exit mirror.

4-6. Piezo element with control unit 4-7.

4-8. Optical plate with positioning unit 4-9.

4-10. Acousto-optic modulator with control unit 4-11.

4-12. Input diaphragm.

4-13. Output aperture.

In the restrictive part of the claims, a complex (device) that implements the proposed method, a number of elements present in the prototype device, is placed in separate blocks. These items include the following:

1. The optical filter pos.6, figure 1 in the prototype device was part of the photodetector blocks 9, 10.

2. The laser radiation modulator pos.30, figure 1 with the control unit 31 in the prototype device was part of the laser generator (laser generator with a laser modulation device).

3. The control unit of the complex pos.25, figure 1 in the prototype device was part of the module of photodetector devices - photodetector unit.

The principle of operation of the proposed method of laser space communications is as follows. Laser communication is established between the base (pos. 2-1 in figure 2) and airborne (pos. 2-2) parts of the complex, installed respectively on the base spacecraft (BKA) 2-3 and on the second spacecraft 2-4 onboard parts complex. Spacecraft are in outer space and move under the influence of gravitational forces of the Sun and planets.

The distance between the first and second spacecraft (SC) can reach from several units to tens of astronomical units (au), where 1 au = 150 · 10 ⁶ km is equal to the average distance from the Earth to the Sun. Laser communication at such long distances can be realized through the use of a special narrow-band laser (quantum) amplifier in the receiving devices, which has the ultimate quantum sensitivity, limited by the quantum nature of electromagnetic radiation. Implementation of the ultimate quantum sensitivity in the optical and near infrared ranges allows for stable reception of the laser information signal at an energy level corresponding to the presence of 2-3 photons per one bit of transmitted information at the input of the receiving optical antenna, which allows full use of the high potential of laser radiation and laser systems communication when transmitting large amounts of information.

The indicated highly sensitive laser amplifier with the ultimate quantum sensitivity, called the active quantum filter (ACF) [6, 7], along with high sensitivity has a rather narrow band of reception and quantum gain of laser radiation, reaching Δν ₀ ≈0.01 inverse centimeters [cm ^-1 ], which in terms of the optical range is a very small value. As a result of this, the main problem in the implementation of ACF-based laser space communication is the problem of compensating for the Doppler shift of the optical frequency of laser radiation arising from the mutual motion of the spacecraft between which communication takes place, with speeds reaching the first or second space velocity. In this case, the actual Doppler shift in the optical range significantly exceeds the similar frequency shift in the radio range and can be up to ~ 10 GHz (10 ¹⁰ Hz).

To solve the problem and implement long-range space laser communication based on highly sensitive ACFs under conditions of large values of the Doppler shift of the optical frequency of the received laser radiation, the following operations are performed.

In order to ensure the functioning of the laser-space communication complex, the transmitting and receiving optical antennas of the base and onboard parts of the complex are mutually oriented, as a result of which the relative position of the base 2-1, FIG. 2 and the onboard 2-2 parts of the complex is set as shown in FIG. 2. Mutual orientation is carried out using slewing devices 2-11, 2-12, as well as by maneuvering and orienting spacecraft 2-3, 2-4. Moreover, data on the position of the spacecraft 2-4 relative to the base SC 2-3 and, accordingly, data on the position of the base SC 2-3 relative to SC 2-4 are received from the external target designation unit 29 and from the motion determination unit 26. Block 29 is a specialized memory device, for example, based on a personal computer, in which the initial data on the parameters of the trajectory of the motion of both spacecraft 2-3, 2-4, as well as information on the time moments of the beginning of the motion of the spacecraft 2-3, 2- 4 along a given path. These data are stored in block 29 of external target designation by the operator or these data are transmitted to block 29 via a special radio channel in the form of telemetry information. Next, in the block for determining the motion parameters 26 on each of the spacecraft 2-3, 2-4 for a given point in time t _{0 the} beginning of the establishment of space communications determine the location of the corresponding spacecraft 2-3 or 2-4 on its trajectory, also determine the location of the spacecraft on the celestial sphere relative to another spacecraft and, accordingly, the direction in space to the corresponding spacecraft 2-3 or 2-4 relative to another spacecraft. This information allows mutual orientation of the optical antennas of the base and onboard parts of the complex. After this operation, they determine the speed V _{1 of the} onboard part of the complex relative to the base part of the complex. This operation is carried out in the base part of the complex (pos. 2-1, figure 2) in the block for determining motion parameters 26 of the base part of the complex. Block 26 includes an electronic computer (COMPUTER), in which based on information received from block 29 on the parameters of the trajectory of the first and second spacecraft, as well as on time t ₀ - the beginning of communication and the current time from the exact time system determine the speed of movement V ₁ KA 2-4 relative to KA 2-3 in the direction of the line of mutual sighting of spacecraft, which is a straight line connecting directly the base and onboard parts of the complex. In Fig.2, the line of mutual sighting is presented in the form of a segment O ₁ -O ₂ . The block of the exact time system is also part of the block 26 for determining motion parameters. Figure 2 in the form of a vector V ₁ shows the speed of the onboard part of the complex 2-2 in the coordinate system associated with the base part of the complex, in which the base part of the complex is stationary. Thus, the speed V ₁ is the radial velocity of the onboard part of the complex relative to the base part of the complex and determines the presence of a Doppler shift of the carrier optical frequency during laser communication between the base and onboard parts of the complex. Next, in block 26 of the base part of the complex, the Doppler shift of the optical frequency Δf _{d of} laser radiation from the base part of the complex is determined when it is received in the side of the complex according to the following formula:

where V ₁ is the previously measured speed of the onboard part of the complex relative to the base part of the complex in the direction of the mutual sight line connecting the base and side parts of the complex; c is the speed of light; f ₀ is the optical frequency of the laser radiation generated in the base part of the complex and emitted along the line of sight O ₁ -O ₂ , figure 2 - in the direction of the side of the complex. When approaching the base and side parts of the complex in the formula (1), the speed V ₁ has a positive sign. When removing the side of the complex V ₁ has a negative sign.

Thus, the measurement of the Doppler shift of the optical frequency according to the formula (1) represents such a shift in the optical frequency that will occur when laser communication is performed between the base and onboard parts of the complex moving with a relative radial velocity V ₁ and when using laser radiation for communication with an optical frequency of f ₀ .

Next, laser radiation is generated in the base part of the complex with an optical frequency shift Δf ₁ by a negative value of the above (earlier) Doppler frequency shift Δf ₁ = -Δf _d . As a result, the optical frequency f _{G1 of the} generated radiation in the base part of the complex is equal to:

Hereinafter, the “unit” index means that the frequency value (f) belongs to the base part of the complex, and the “two” index means that the frequency or frequency shift belongs to the airborne part of the complex, respectively.

If the onboard part of the complex is removed from the base part, the Doppler shift according to (1) has a negative sign, and the generated optical frequency f _Г1 according to (2) exceeds the initial optical frequency f _{0 of the} laser transition of the used working substance of the laser generator by the magnitude of the Doppler frequency shift modulus | Δf _d |:

The shift of the optical frequency in the base part of the complex is carried out simultaneously with the generation of laser radiation using a laser generator with frequency tuning (LGPCH) pos.21 in figure 1. The control signal in digital form enters the LGPCH 21 from the output of the control unit 25 of the base part of the complex. In the control unit 25, information about the magnitude of the Doppler shift Δf _{d is} received from the output of the motion parameter determination unit 26. In the control unit 25, this information is converted into a special control code LGPCH 21 and at a given point in time is fed to the control input LGPCH 21.

Thus, LGPCH 21 generates (generates) laser radiation, the optical frequency f _{G1 of} which corresponds to the value specified in formulas (3; 2). Formed in the base part of the complex, the laser radiation from the output of the LGPCH 21 is fed to the optical antenna 4, Fig. 1 and pos. 2-5, Fig. 2 and then is emitted to the side of the complex, pos. 2-2 in Fig. 2.

Further, in the side part of the complex, this radiation is received using an optical receiving antenna, pos. 1 in Fig. 1 and, accordingly, pos. 2-7 in Fig. 2. Upon receiving the laser radiation it receives from the optical receiving antenna 1 input AKFPCH 5, 1, wherein the amplification is carried quantum received laser radiation within a band reception and quantum amplification AKFPCH the central (middle) band frequency f _p2 receiving AKFPCH equal first frequency f ₀ of the quantum transition of the laser medium (working medium) and AKFPCH LGPCH laser oscillator 21 in an undisturbed condition: f ₀ = f _p2. This optical frequency of the quantum transition also determines the optical frequency f _{0 of the} reference laser generator 17.

Next, in the side part of the complex, the shift Δν _{2 of the} optical frequency of the received and amplified laser radiation relative to the reference optical frequency f _{0 of the} reference laser radiation generator 17 is measured. To do this, the amplified received laser radiation from the output of the AFPCR 5 through the optical filter 6 and translucent mirrors 13, 16 is fed to the input of the first unit for measuring the optical frequency 12. At the same time, laser radiation from the reference laser generator 17 with the reference optical frequency f is fed to the second input of the unit 12 ₀ . Laser radiation enters through translucent mirrors 19 and 20. The first optical frequency measurement unit 12 measures the shift _{of the} optical frequency Δν ₂ , information about which is digitally transmitted from the output of block 12 to the input of the control unit of complex 25, for which, for example, standard computer (or personal computer). The magnitude of the measured shift Δν ₂ optical frequency is

where f _CR2 is the optical frequency of the received laser radiation, which is determined by the optical frequency of the laser radiation generated and emitted by the base part of the complex f _Г1 (2) and the value of the real Doppler shift

Here V _R is the real value of the speed of movement of the onboard part of the complex relative to the base part of the complex. In the general case, the previously measured speed V ₁ of the onboard part of the complex relative to the base part of the complex may differ from the real speed V _R due to errors in estimating the value V _{1 of the} speed of the relative movement of the side part and the base part of the complex according to trajectory measurements made earlier in the base part of the complex .

The value of f _CR2 is equal to

As a result, the measured shift Δν ₂ (4), taking into account (5) and (6), is equal to:

The second term in (7) is a second-order quantity of smallness and will be omitted below. Thus, the magnitude of the measured shift Δν _{2 of the} optical frequency characterizes the error in determining the Doppler frequency shift in the base part of the complex (1), due to possible inaccuracy in the initial determination of the speed V _{1 of the} movement of the side of the complex relative to the base of the complex. The shift value Δν _{2 of the} optical frequency, measured in the side part of the complex, is further used to compensate for the indicated possible error in determining the speed of movement V ₁ . To do this, the generation of laser radiation in the onboard part of the complex is carried out with a shift of the optical frequency Δf ₂ by a negative value of the measured shift of the optical frequency Δν _{2 of the} laser radiation received from the base part of the complex:

Information about the measured value Δν ₂ comes from the output of the first optical frequency measuring unit 12 to the control unit of the complex 25 and then at the corresponding time to the control input of the LGPCH 21. At the same time, the control unit 25 generates a control signal that provides a shift of the generated frequency of the laser radiation of the LGPCH 21 by value (8). As a result, the laser radiation generated in the onboard part of the complex in the LGPH has an optical frequency f _Г2 equal to:

where the values of f ₀ , V ₁ , V _R correspond to similar values in the formula (7).

Simultaneously with the shift of the generated frequency of the laser radiation in the onboard part of the complex in LGPH 21, additional modulation of the generated laser radiation is carried out by the measured frequency shift Δν ₂ . This operation is carried out with the aim of transmitting information about the measured value Δν ₂ from the onboard part of the complex to the base part of the complex. This additional modulation is carried out simultaneously and in parallel with the modulation of laser radiation in the laser radiation modulator 30 with an information signal coming from the information source unit 28 through the control unit of the complex 25.

Next, the subsequent reception and quantum amplification of the laser radiation received in the onboard part of the complex by means of a receiving optical antenna 1 (Fig. 1) is carried out with a shift of the center frequency f _{2 2} of the reception band in the AFPC 5 by the measured shift Δν _{2 of the} optical frequency of the received laser radiation. To carry out this shifting the center frequency f _p2 band reception AKFPCH 5 measured by the amount of shift Δν _two optical frequencies, information about the value which is output from the control unit 25 set the control input AKFPCH 5.

Thus, as a result of the last three operations in the onboard part of the complex, the generated frequency of the laser radiation is shifted by Δν ₂ , the center frequency of the reception band and the quantum amplification of laser radiation is shifted by Δν ₂ , and information on the measured value of Δν ₂ is transmitted back from the airborne to the base of the complex. These operations provide compensation for a possible error of the primary determination (estimation) of the speed V _{1 of the} movement of the side part relative to the base part of the complex.

Further, in the base part of the complex, laser radiation is received from the onboard part of the complex with a previously realized shift of the generated optical frequency and modulation of this laser radiation with a shift value of Δν ₂ . Laser reception in the base part is carried out using the receiving optical antenna 1 in the base part of the complex (pos. 2-6 in FIG. 2), the radiation from which goes further to the optical input of the AFPCh 5, FIG. 1. Next, quantum amplification of this laser radiation is carried out in AFCF 5 with a shift of the center frequency f _f1 of the reception band in AFCF 5 in the base part of the complex by the value of the previously measured Doppler frequency shift Δf _d (1):

To implement this quantum amplification of laser radiation with the indicated parameters of the reception band, information about the measured value of the Doppler shift Δf _{d is} supplied from the output of the control unit of complex 25 to the control input of the AFPC 5, where, under the action of this control signal, the center frequency f _f1 of the reception band is shifted by a value earlier measured in the base part of the complex of the Doppler shift Δf _d (1). This provides compensation for the Doppler shift of laser radiation received in the base of the complex and emitted in the side of the complex in accordance with the Doppler shift Δf _d (1), the value of which (estimate) was obtained earlier as a result of the initial determination of the speed of movement V _{1 of the} side of the complex relative to the base parts of the complex.

Next, in the base part of the complex, the shift Δν _{1 of the} optical frequency of the laser radiation received and amplified by the AFCF 5 is measured relative to the reference optical frequency f _{0 of the} reference laser radiation generator 17. This measurement of Δν _{1 is} carried out using the first optical frequency measurement unit 12, to the optical inputs of which receives the received and amplified laser radiation from the output AKFPCH 5 through the half mirror 13 and the reflecting mirror 16, and enters the laser light with the reference optical frequency f ₀ with Exit reference laser generator 17. Information about the measured value of the optical frequency shift Δν is output from the first optical frequency measurement unit 12 is input to the control unit 25. The measured complex value Δν ₁ shift the optical frequency of the laser radiation received at the base portion of the complex and radiated in the side part of the complex is equal to (4-7):

Where

f _CR1 is the optical frequency of the laser radiation received in the base part of the complex.

Here

- Doppler shift of laser radiation corresponding to the real speed V _{R of the} side part relative to the base part of the complex.

After measuring the shift Δν ₁ in the base part of the complex, the laser radiation is demodulated from the side of the complex, as a result of which information is obtained on the amount of shift Δν _{2 of the} optical frequency of the laser radiation, which was previously measured in the side of the complex and in accordance with which additional modulation was performed generated in the side of the complex laser radiation. The received laser radiation is demodulated using the first photodetector unit 9, Fig. 1 or a multi-channel laser communication unit 11. Information about the shift Δν ₂ in digital form comes from the output of the FPB 9 to the control unit of the complex 25, into which the output of the first optical measurement unit frequency 12 also receives information about the measured shift Δν ₁ optical frequency (11). Thus, the control unit of complex 25 in the base part of the complex receives information about the values of the shifts of the optical frequency of the laser radiation received and measured in the side of the complex — shift Δν ₂ (7) and shift Δν ₁ (11), measured in the base part of the complex .

Further, on the basis of the obtained values of the optical frequency shifts Δν ₁ , Δν ₂ , the parameters of the laser cosmic communication mode are determined in accordance with the following relationships:

where Δf _d is the Doppler shift of the optical frequency measured earlier in the base part of the complex (1).

According to the obtained values of the parameters of the laser communication mode ε ₁ and ε ₂ judge the quality of the established laser space communications, namely:

subject to the conditions

decide on the establishment of a regular laser communication mode between the base and onboard parts of the complex with a satisfactory level of communication quality.

After this decision is made, two-way transmission of information between the base and onboard parts of the complex is carried out by modulating the generated laser radiation in the LGPCH 21 both in the base part and on the side of the complex with information signals entering the LGPCH 21 from the information source 28 through the complex control unit 25 . At the same time, in the base and onboard parts of the complex, shifts of the optical frequencies of the generated laser radiation in LGPCH 21 and shifts of the central frequencies of the reception band in the AFCHR 5 established during the entry into the space communication mode are used.

If at least one of the conditions (16), (17) is not fulfilled, a second cycle of establishing a laser space communication between the base and onboard parts of the complex is carried out in accordance with the above stated method, and the amount ₍ use) of the amount ( _D ) of the optical frequency shift Δf _{d is} used (accepted) measured optical frequency shifts

Then, after checking the fulfillment of conditions (16), (17) on the second cycle of establishing laser-space communication, when relations (16), (17) are fulfilled, the process of establishing laser communication according to this method is completed and two-way information is continuously transmitted between the base and onboard parts of the complex.

As a result of the operations performed in the base and onboard parts of the complex, the optimal mode of tuning and functioning of the transmitting and receiving elements of the complex is implemented. This mode is characterized by accurate compensation of the Doppler shift, as a result of which the frequency of the optical carrier of the laser radiation received in the airborne and base parts of the complex exactly corresponds to and is equal to the center frequency of the reception and quantum gain frequency AFPC 5, respectively, in the airborne and base parts of the complex. In this case, the regime of the limiting quantum sensitivity is realized in AFCF 5 and the maximum possible quantum gain bandwidth in AFCF, reaching, for example, in the AFCF based on a photodissociation iodine laser, Δf _И = 300 MHz. Moreover, the amount of information transmitted is about 300 Mbit · s ^-1 .

Compensation for the Doppler shift is ensured by the following basic operations: determining the radial velocity V _{1 of the} side part relative to the base part of the complex; determining the Doppler shift Δf _{d of} the laser frequency; the forward shift Δf _{1 of the} frequency of the emitted laser radiation in the base part of the complex; determining the shift Δν _{2 of the} frequency of the received laser radiation, as well as establishing a preemptive shift Δf _{2 of the} frequency of the emitted laser radiation in the onboard part of the complex, measuring the shift Δν _{1 of the} received laser radiation in the base of the complex. Moreover, regardless of the accuracy of the preliminary measurement of the radial velocity V ₁ , that is, regardless of the magnitude

when the shift value Δν ₂ (7) in the onboard part of the complex is accurately determined and compensation is made by setting the corresponding shift of the optical frequency of the generated laser radiation in the onboard part of the complex by Δf ₂ = -Δν ₂ (8), the optimal laser reception mode is realized in the base and onboard parts of the complex with pre-installed additional compensation for the Doppler frequency shift between the onboard and base parts of the complex by Δf ₂ = -Δν ₂ . Indeed, according to relation (7), the measured shift of the optical frequency Δν ₂ in the onboard part of the complex is equal to the difference of the Doppler shifts:

that is, the difference between the real Doppler shift Δf _R1 , and the measured Doppler shift Δf _d obtained by measuring (estimating) the radial velocity V ₁ . Therefore, the implementation of the frequency shift of the laser radiation generated in the side part of the complex by Δf ₂ = -Δν ₂ provides accurate compensation for the Doppler shift when receiving laser radiation from the side part in the base part of the complex due to the fact that in the base part of the complex after determining the Doppler shift Δf _d based on the measured radial velocity V ₁ implemented shift the center frequency f _Q-1 and the reception band emission in quantum amplification AKFPCH 5 complex base portion just by the amount measured before lerovskogo shift Δf _d (1), and this operation is effected prior to receiving laser radiation from the bead portion. Resulting center frequency

f _f1 of the reception band in the AFPCh 5 in the base of the complex is exactly equal to the optical frequency f _pr1 (12) of the received laser radiation in the base of the complex from the side of the complex, taking into account the presence of real Doppler shift due to the real radial speed V _R and the established frequency shift Δf ₂ = -Δv _{2 of} laser radiation generated and emitted in the side of the complex.

Similarly, in the bead portion of the complex to establish shear center frequency f _p2 reception band AKFPCH the measured value Δν ₂ (7) provides exact equality (coincidence) of the center frequency f _p2 reception band with an optical frequency f _np2 (6) of the received laser radiation in the bead portion of the complex from the base of the complex, taking into account the real Doppler shift Δf _R and the set shift Δf _{1 of the} optical frequency f _{G1 of the} laser radiation generated and emitted in the base of the complex, Δf ₁ = -Δf _d .

Indeed, the optical frequency f _pr2 received in the onboard part of the laser radiation complex is equal according to (6):

At the same time, the center frequency of the radiation reception band in the AFPCh 5 in the onboard part of the complex, taking into account the established shift of the center frequency of the reception band by Δv _2, is equal to:

It should be noted that this value of the center frequency of the reception band in the AFPCh 5 in the onboard part of the complex was established after receiving laser radiation from the base part and measuring a shift Δν _{2 of the} optical frequency of this radiation relative to the reference optical frequency f _{0 of the} reference laser generator 17. The initial reception of laser radiation in the onboard part of the complex is carried out, as noted above, with the central frequency f _c2 of the reception bandwidth set in the AFCF 5 equal to the reference optical frequency f _{0 of the} reference laser generator 17 and correspondingly equal to the optical frequency f ₀ of the active substance working transition in the LGPH and AKHPH:

The optical frequency f _np2 received laser radiation in the bead portion of the complex (6) should fall within the reception band and quantum amplification AKFPCH 5 when the value of the center frequency f _n2 AKFPCH in 5 equal to f _0. This implies the following requirement for the accuracy of determination of the Doppler shift Δf _d obtained on the basis of the measurement of the radial velocity V ₁ (1):

where P is the width of the reception band and the quantum gain of laser radiation in the AFCF 5, which is some technical parameter of the AFCF determined by the properties of its working active substance, the pump mode, and in the standard AFCF operation mode, is equal to, as noted above, P = 300 MHz. Accordingly, condition (24) is also a requirement for the accuracy of determining the radial speed of movement V ₁ relative to the real value of the radial speed V _R.

If condition (24) is not satisfied, that is, the accuracy of determining the radial velocity V ₁ and the Doppler shift Δf _{d is} not sufficient for the optical frequency f _{pr2 of the} received laser radiation to _fall into the reception band P and quantum gain in the AFPC 5, then the reception operation in the side part of the complex laser radiation and measuring its shift Δν ₂ relative to the reference frequency f ₀ cannot be performed. In this case, in the onboard part of the complex proceed as follows and perform the following operations.

In the absence of a signal at the output of the first optical frequency measuring unit 12, the control signals from the control unit of complex 25 of the AFPCR 5 are transferred to the scanning mode of the center frequency f _c of the laser reception band. The scanning mode is characterized by the fact that the central frequency of the reception bandwidth f _c is changed over time in the AFPCR 5, for example, according to a linear law, that is, proportional to the time t, until the time t _{2 of the} appearance of the signal at the output of the first optical frequency measurement unit 12. Next, at time t ₂ is stopped by the process of changing the center frequency of receiving band in AKFPCH been achieved value f _n is measured shift amount Δν ₂ optical frequency of the received laser light and then perform the entire cycle of operations SET eniya laser communications in the vehicle and the base portions of the complex, after the above measurement operation of the optical frequency shift Δν ₂ in the bead portion of the complex.

Thus, the reception and quantum amplification of laser radiation in the AFFC 5 in the onboard part of the complex is carried out in two versions. In the first embodiment, the reception is carried out in AFCCH 5 with the center frequency of the reception bandwidth set in the AFCCH until the optical frequency of the received laser radiation falls into the reception band P of the AFCCH. The selection criterion for the first or second reception options in the AFCHR is the presence of a signal at the output of the first optical frequency measuring unit 12 (the first option for receiving laser radiation) or the absence of such a signal (second reception option).

It should be noted that the reception of laser radiation in the base part of the complex using AFCF 5 is carried out in a single embodiment with a set center frequency shift f _f1 of the reception band in AFCF 5 equal to the measured Doppler shift Δf ₁ = Δf _d (1). In this case, due to the established shift Δf ₂ = -Δv _{2 of the} frequency of the laser radiation generated in the onboard part of the complex, the optical frequency f _{pr1 of the} laser radiation received in the onboard part of the complex will be equal to the corresponding set value of the central frequency of the reception band in the AFPC 5:

The optical frequency shift Δν ₁ (11) measured in the base part of the complex is a control parameter and allows us to judge the accuracy of two basic operations in the onboard part of the complex in the base part of the complex: the operation of measuring the shift of the optical frequency Δν ₂ and the shift of the optical frequency of the generated laser radiation in the onboard part of the complex by a value of Δν ₂ . When the above two operations are accurately performed on the side of the complex, the measured shift Δν _{1 of the} optical frequency f _{pr1 of the} received laser radiation is exactly equal to the value measured at the base of the Doppler shift complex Δf _d (1). According to (11)

.

.

Accordingly, the first parameter of the laser communication mode ε ₁ (14) characterizes the quantitative level of accuracy of operations in the onboard part of the complex on the basis of calculating the difference between the measured shear value Δν ₁ and the previously obtained value of the magnitude of the Doppler shift Δf _d (1) with respect to the absolute value of this Doppler shift.

Accordingly, the sum of the shifts of the optical frequency Δν ₁ , Δν ₂ measured in the base and side parts of the complex with accurate measurement and the exact introduction of the frequency shift Δf _{2 of the} generated laser radiation in the side of the complex is equal to the real Doppler shift

и измеренной в базовой части величиной доплеровского сдвига Δf_d (1) на основании измерения (оценки) радиальной скорости V₁. Поэтому величина второго параметра ε₂ (15) режима лазерной связи характеризует точность первичного определения доплеровского сдвига Δf_d по отношению к реальной величине доплеровского сдвига

, так как измеренная величина сдвига Δν₂ (7) характеризует собственно разность величин реального и измеренного Δf_d доплеровских сдвигов. Соответственно отсюда при выполнении (16), (17) принимается решение о достижении заданного качества установления штатного режима лазерной связи между базовой и бортовой частями комплекса. При невыполнении условий (16), (17) принимается решение о проведении второго дополнительного цикла установления лазерной космической связи, при этом в качестве действующей величины доплеровского сдвига оптической частоты Δf_d=Δf_d2 на втором данном цикле используют сумму измеренных сдвигов оптической частоты Δf_d2 (18), которая является в этом случае более точной оценкой величины реального доплеровского сдвига. Таким образом, согласно предложенному способу за один цикл выполнения операций по установлению связи в базовой и бортовой частях комплекса осуществляют точную компенсацию доплеровского сдвига оптической частоты лазерного излучения, а также осуществляют определение точности выполнения этой компенсации, что позволяет при необходимости осуществить второй дополнительный цикл установления лазерной космической связи для реализации более точной компенсации доплеровского сдвига оптической частоты используемых в базовой и бортовой частях комплекса лазерных излучений.The shift Δν ₂ (7) characterizes the difference between the real value of the Doppler shift

and the value of the Doppler shift Δf _d (1) measured in the base part based on the measurement (estimation) of the radial velocity V ₁ . Therefore, the value of the second parameter ε ₂ (15) of the laser communication mode characterizes the accuracy of the initial determination of the Doppler shift Δf _d with respect to the real value of the Doppler shift

, since the measured shift Δν ₂ (7) characterizes the actual difference between the real and measured Δf _d Doppler shifts. Accordingly, when fulfilling (16), (17), a decision is made to achieve the specified quality of establishing a regular laser communication regime between the base and onboard parts of the complex. If conditions (16), (17) are not fulfilled, a decision is made to conduct a second additional cycle of establishing laser space communications, while the sum of the measured shifts of the optical frequency Δf _{d2 is} used as the effective value of the Doppler shift of the optical frequency Δf _d = Δf _d2 18), which in this case is a more accurate estimate of the magnitude of the real Doppler shift. Thus, according to the proposed method, for one cycle of operations to establish communication in the base and onboard parts of the complex, exact Doppler shift of the optical frequency of laser radiation is carried out, and the accuracy of this compensation is determined, which allows, if necessary, a second additional cycle of establishing laser space communication to implement more accurate compensation for the Doppler shift of the optical frequency used in the base and onboard parts x complex laser radiation.

Further, in the base and onboard parts of the complex, simultaneously with the two-way transmission of information at the optical frequency, they continuously monitor the real value of the Doppler shift Δf _R in accordance with the operations of the above method, and also continuously compensate for the Doppler shift, which provides support for a high-quality laser-space communication mode, for example when moving the airborne or base parts of the complex along a space trajectory (orbit around a planet or the Sun), in which dit the time variation value of radial velocity V _R.

Consider a number of modifications of the proposed method of laser space communications, aimed at simplifying and reducing the composition of the equipment located in the side of the complex.

The first version of the modification of the proposed method of laser space communication is that in the onboard part of the complex using a laser generator (LG), as well as an active quantum filter (ACF) without frequency tuning. In this case, the composition of the equipment decreases, and the composition of operations performed in the onboard part of the complex also decreases.

The sequence of operations of the first modified method of laser space communications has the following form. In the airborne and base parts of the complex, the receiving and transmitting antennas are mutually orientated similarly to the basic version of laser space communication described above. Next, in the onboard part of the complex, laser radiation is generated with an optical frequency f ₀ corresponding to the frequency of the working transition of the active substance used in LGPCH and AHFPC in the base part of the complex. The laser radiation formed in the airborne part is directed by means of a transmitting optical antenna towards the base part of the complex. Simultaneously, the reception of laser radiation from the base of the complex in the onboard part of the complex is carried out using ACF without tuning the frequency with a center frequency f _c of the ACF reception band equal to the optical frequency f _{0 of the} working transition of the active substance in LG:

In the base part of the complex, the radial velocity V ₁ is determined, and the Doppler shift Δf _d (1) is also determined on its basis similarly to the main version of the laser-space communication method described above.

Then, in the base part of the complex, radiation is received from the onboard part of the complex using AFCF 5, while the center frequency f _f1 of the receive band in AFCF 5 is shifted by the measured Doppler shift Δf _d at which the center frequency of the receive band in AFCF 5 is

Next, in the base part of the complex, the frequency shift Δν _{1 of} the received and amplified laser radiation is measured from the output of the AHFCH 5. Since the laser radiation with the optical frequency f _{0 is} generated and directed towards the base part of the complex, the obtained frequency shift Δν ₁ is accurate estimation of the real Doppler frequency shift Δf _R = Δν ₁ between the base and onboard parts of the complex.

Next, in the base part of the complex, laser radiation is generated using LGPH with a shift of the optical frequency of the generated laser radiation Δf ₁ = -Δν ₁ by a negative value of the measured frequency shift Δν ₁ , and therefore by a negative value of the measured real Doppler shift Δf _R = Δν ₁ . This formed in the base portion of laser radiation with a frequency f _r1 = f ₀ -Δf _R directed towards the sides of the complex, where the reception is carried out of the laser radiation via the ACF with a central receiving frequency band f _p2 = f _0. Due to the presence of a Doppler frequency shift Δf _R between the base and onboard parts of the complex and the establishment of a shift Δf ₁ = -Δν _{1 of the} generated frequency opposite to this Doppler shift, exact compensation of this shift is realized and the laser radiation received in the onboard part of the complex falls exactly in the ACF reception band with center frequency

f _n = f _0, i.e., the optical frequency f _direct laser radiation received at the sides of the complex autocorrelation function is equal to the center frequency f _ave = f _p2 = f _0. Then in the base and onboard parts of the complex transmit and receive laser radiation modulated by information signals with the set values of the shifts of the generated frequency and the central frequency of reception in the base part of the complex.

In the first modified version of the laser space communication method presented, all operations for measuring the optical frequency shifts and compensating for the measured Doppler shift in the LGPCH and AFPCH are performed in the base part of the complex, and the LG laser generator and ACF with fixed parameters of the generated and received frequencies are used in the side part of the complex f ₀ . This allows you to improve the operational technical characteristics of the onboard part of the complex (weight, dimensions, etc.), however, in this embodiment of the method of laser space communication there is no possibility of operational control of the accuracy of compensation for Doppler frequency shift.

To realize this possibility, a second modified version of the method of laser space communication is proposed, which differs from the first version by the addition of the following operations. Firstly, in the onboard part of the complex after receiving laser radiation from the base part of the complex, the frequency shift Δν _{2 of the} received laser radiation relative to the reference frequency f ₀ is determined.

Next, the magnitude of the measured frequency shift Δν ₂ is digitally sent from the onboard part to the base part of the complex by modulating this information with laser radiation in the laser modulation unit 30, Fig. 1 in the side part of the complex.

Secondly, in the base part of the complex, laser radiation is received and demodulated from the onboard part of the complex, and the obtained frequency shift value Δν _{2 is} used to check (analyze) the accuracy of Doppler shift compensation, for which the following laser communication mode parameter is determined in accordance with the ratio:

This parameter is an analogue of the corresponding parameter ε ₂ (15) in the main version of the method of laser space communication and, like ε ₂ , characterizes the accuracy of compensation for the Doppler shift through the reaction of the laser receiving object — the airborne part of the complex. In this case, the shift value Δν _2, similarly to (7), reflects the difference between the real value of the Doppler shift along the base – side part of the complex and the shift of the optical frequency Δf ₁ in the LHPS in the base part of the complex, which was introduced for preliminary compensation of the Doppler shift during laser generation radiation in the base of the complex. Accordingly, the magnitude of the shift of the optical frequency measured in the base part of the complex Δν ₁ when receiving laser radiation from the onboard part of the complex directly determines the magnitude of the real Doppler frequency shift Δf _R.

Hence, the ratio ε ₃ = Δν ₂ / Δν ₁ (29) in the second modified version of the method of laser space communication corresponds to and is equal to the ratio ε ₂ (15) in the main method of laser space communication. Therefore, the fulfillment of the condition for ε ₃ (29):

similar to condition (17) and characterizes the accuracy of the compensation of the Doppler shift between the base and side parts of the complex.

Relation (14) for Δν ₁ in the considered second modified version of the method characterizes, similarly to the main version of the laser-space communication method, the accuracy of the initial determination of the Doppler shift according to external target designation, trajectory measurements, etc.

This parameter ε ₄ in the second modified version of the method is also determined in the base part of the complex. Further, as a result of the analysis of the obtained parameters ε ₃ (29) and ε ₄ (31) in the base part of the complex in the control unit 25 under the conditions

decide on the completion of the laser space communications establishment cycle.

Thus, the stated main method of laser space communication and the first and second modified versions of the method of laser space communication include the same operations in the base or onboard parts of the complex. The transfer of part of these operations from the onboard to the base of the complex allows to reduce the composition of the equipment in the onboard part of the complex. At the same time, the distribution of the operations performed between the base and onboard parts of the complex in the main method allows for high accuracy of compensation for Doppler shift and at the same time provides control of the accuracy of compensation and operational adjustment of the compensated parameters in the base and onboard parts of the complex, which allows for high accuracy of compensation under changing conditions in time the parameters and trajectories of the motion of spacecraft carrying the base and onboard parts of the complex.

The proposed method of laser space communication through the use of highly sensitive quantum amplification of received information laser signals and by providing accurate compensation for the Doppler shift allows for the transfer of large amounts of information over long space distances, that is, to increase the range of laser space communication while increasing the speed and volume of transmitted information , as well as providing the necessary reliability and reliability of communication. High sensitivity and information transfer rate are ensured by the AFCF, which is used, for example, as a laser (quantum) amplifier based on a photodissociation laser [6, 7], which has a limit quantum sensitivity limited by a quantum limit, that is, it has the ability to receive single-photon pulsed signals with amplitude -pulse or pulse-polarization modulation of laser radiation with a digital information signal. Reception of the laser radiation amplified in the AFCF with such modulation and its demodulation is carried out using the first and second photodetector blocks, items 9, 10 in FIG. 1. The speed of information transfer by laser radiation with this type of modulation for this type of AFPCR is about 300 Mbit per second. At the same time, to ensure the necessary reliability and reliability of communication with the probability of correct detection of 0.999 at the AHRC input, it is enough to have 3 photons per bit of information on the input aperture of the receiving optical antenna [7], which corresponds to a signal-to-noise ratio m equal to m = 3 input energy laser signal E _Rin = mhν, three photons of energy corresponding to the wavelength λ ₀ = c / f ₀ at the input aperture receiving optical antenna. The problem solved by the proposed method is to ensure the operation of the AHFCH in a highly sensitive mode of receiving weak laser signals under conditions of mutual movement of the base and onboard parts of the complex with cosmic velocities, which is implemented by compensating for the Doppler frequency shift of the received laser information signals. The use of high-sensitivity AFCPT in a wide frequency band allows the use of a multi-channel laser communication unit 11, Fig. 1 with frequency channel multiplexing and a laser heterodyne method of receiving and converting information signals at an optical carrier frequency in the base and onboard parts of the complex. The use of quantum amplification of the received laser radiation before the laser heterodyning in the AFCF allows eliminating the influence of the intrinsic noise of the laser local oscillator and providing high-quality reception of a broadband information signal with frequency channel multiplexing while maintaining this high sensitivity at the AFCF input. This overcomes the well-known drawback of the heterodyne method of receiving signals in the optical range, associated with the influence of the intrinsic (quantum) noise of the laser local oscillator, which does not allow the reception of broadband laser information signals with high sensitivity. Thus, the use of a highly sensitive AFPC with compensation for Doppler frequency shifts makes it possible to provide broadband laser communication on long-distance cosmic paths using various modern highly effective methods for modulating laser signals, including amplitude-pulse (code-pulse) direct laser radiation modulation (FPB - 9, 10) , as well as various methods for modulating an optical carrier using a microwave subcarrier and a laser heterodyne method for receiving optical signals (block 11).

The range of the proposed complex laser space communications can be determined by the following formula [8]:

where E _n is the pulse energy of the laser transmitter (LGPCH), necessary to transmit one bit of information; N _min = hν = h / λ ₀ is the energy of one noise photon reduced to the input of the AHFR and determining the level of the ultimate quantum sensitivity of the AHFH corresponding to the reception of a single-photon pulse signal with 1 bit of information; ε is the value of the signal-to-noise ratio at the input of the optical antenna, item 1, figure 1. For reliable reception of information, it is necessary to provide a value of ε = 3; R is the range of the laser space communications complex - the maximum distance between the base and onboard parts of the complex; D _n , D _CR - the diameters of the transmitting and receiving optical antennas of the complex.

квантового усиления излучения в АКФПЧ [7]. Соответственно мощность ЛГПЧ в непрерывном режиме работы равна:Formula (33) determines the energy per bit and, accordingly, the power of the LGPH necessary to provide laser communication at a distance R between the base and onboard parts of the complex. In this case, it is assumed that Doppler frequency shift compensation has been implemented and the laser receiving device of the complex - AFPCh 5 - operates in the mode of ultimate quantum sensitivity, characterized by the energy of one noise photon N _min = hν ₀ = h / λ ₀ for a time Δτ = 10 ^-9 s determined by the bandwidth

quantum amplification of radiation in the AFCHR [7]. Accordingly, the power of LGPCH in continuous operation is equal to:

The following are the parameters of the laser-space communications complex for various space routes, starting from near space - within the orbit of the moon and to the far borders of the solar system - to the orbit of Pluto. The diameters D _n and D _{pr of the} transmitting and receiving optical antennas and the required power of the laser transmitters, as well as the laser pulse energy per one bit of the transmitted information are given.

1. Earth-Moon space communication system

2. Space communications system Earth - satellite of the Earth in a stationary orbit

3. Earth-Mars space communications system

4. Earth-Pluto space communications system to the borders of the solar system

The presented parameters of the laser space communication complex based on the AFCHF indicate the high efficiency of the proposed method and the LKS complex for its implementation. In the near space to the orbit of the moon, the required energy and power of the laser transmitters is very moderate (P _n = 0.6 mW), which allows the use of a semiconductor laser diode with frequency tuning [9], similar to that used in modern fiber optic, as a laser transmitter a communication system, the volume and speed of information transfer in such a laser space communication system corresponds to the same parameters of broadband fiber-optic communication lines. The most promising is the use of the proposed LKS complex for organizing stationary Earth-Moon communications to provide lunar space stations with broadband communications. A system of laser space communication with the planet Mars is also very promising, which will require a laser transmitter with a power of P _n = 2 W, as well as an LKS system within the solar system to the orbit of Pluto. Thus, the proposed complex of space-based laser communications based on a highly sensitive AFFC allows for highly efficient broadband communication with spacecraft and stations within the solar system and successfully competes with modern radio-frequency space communication systems that are inferior to LSS systems in a number of parameters, for example, in speed and volume of transmitted information. So, for example, the use of the proposed complex of laser space communications in near space to the orbit of the moon makes it possible to increase the speed and amount of transmitted information in comparison with the microwave range by ~ 10 times.

The proposed complex of space-based laser communications based on the AFCHR with the ultimate quantum sensitivity makes it possible in the future to realize hypothetical systems of laser communications with spacecraft throughout our Galaxy, as well as with the Andromeda Nebula galaxy closest to us. The following are the parameters of such space communication systems calculated by the formula (33).

Promising space communications systems

5. Space communication system within the Galaxy

R _G = 10 ⁵ St. years = 9.5 · 10 ²⁰ m

5.1. D _n = D _np = 30 m; E _n = 1.4 · 10 ⁶ J; P _n = 3 · 10 ¹⁴ W

5.2. D _n = D _np = 120 m; E _n = 5.4 · 10 ³ J; P _n = 1,08 · 10 ¹² W

6. Space communication system with the Andromeda Nebula galaxy

R _TA = 1.5 · 10 ⁶ st. summer = 1.42 · 10 ²² m E _n = 1.2 · 10 ⁶ J D _n = D _np = 120 m P _n = 2.4 · 10 ¹⁴ W

Currently, powerful laser generators already exist with the indicated parameters of power and energy used for laser thermonuclear fusion [10]. The diameter of optical antennas (telescopes) has now reached D = 10 m [11]. In the design [12], there are promising designs of telescopes with D _p = 30 m, as well as composite telescopic systems with an effective diameter several times larger than D _p. Thus, the use of AFPCR with the ultimate quantum sensitivity, modern high-power laser transmitter-generators, and advanced optical antenna systems [11] allows us to realize a complex of laser-space communications at ultra-long-distance cosmic distances within our Galaxy at distances of 100 thousand stars years, and to the closest galaxy to us, the Andromeda Nebula, at a distance of 1.5 million light years.

The high range of the proposed complex of laser space communications makes it possible to use it to solve one of the important problems of modern science and technology: the problem of searching for signals of extraterrestrial civilizations [8]. The features of the physical properties of the active substance of photodissociation laser generators and quantum amplifiers - atomic iodine - determine the use of the working wavelength of the quantum transition of atomic iodine λ ₀ = 1.315 μm as a natural reference indicating the wavelength within which to search for signals of extraterrestrial civilizations and establish long-distance space communications.

In the device of figure 1, which implements the proposed method of laser space communication, the generation of laser radiation at a working wavelength λ ₀ = c / f _{0 of the} laser communication is carried out by a laser with frequency tuning (LGPCH). Figure 3 presents a block diagram of one of the possible LGPH embodiments based on a photodissociation iodine laser generator with tuning of the generation frequency [13].

As the working substance in the cuvette 3-1 of figure 3, atomic iodine is used in the gas phase, which is formed as a result of the photodissociation of perfluoroalkyl iodides under the action of radiation from flash pump tubes included in the pump unit 3-2. The working wavelength λ ₀ generated in the LGPH and corresponding to the working laser transition of atomic iodine is λ ₀ = 1.3 μm; radiation frequency f ₀ = s / λ ₀ = 2.3 · 10 ¹⁴ Hz. The frequency tuning of the laser generator in figure 3 is carried out using the control unit of the frequency of generation 3-3, which contains several electromagnets (solenoids) that create a transverse magnetic field in a cell 3-1 with a working substance - atomic iodine. The magnitude of the magnetic field in the cell 3-1 is changed by changing the magnitude of the current in the electromagnets under the action of a control signal received in block 3 from the control unit of the complex 25 of figure 1. Under the influence of a magnetic field in the cell 3-1, the frequency of the generated radiation is smoothly tuned. The achieved shift value Δf of the frequency of the generated laser radiation f _g with respect to the initial generation frequency f ₀ generated at a zero magnetic field H = 0 is

When the magnetic field is turned on, the band of quantum amplification of laser radiation by the active substance in the cell 3-1 of FIG. 3 also expands. For more accurate selection and generation of laser radiation with a given frequency f _g , an optical plate 3-6 of FIG. 3 is used, inserted into the optical circuit of the laser generator in FIG. 3 and oriented at a certain angle φ to the axis O ₁ O _{2 of the} LGPH resonator. This plate 3-6 is a Fabry-Perot interferometer [14], which provides for the selection of one of the longitudinal modes of the resonator with a certain frequency of oscillation (generation). By changing the angle of inclination of this plate 3-6 with respect to the axis of the resonator O ₁ O ₂ , they provide a frequency shift of the generated laser radiation within its quantum gain band, which was previously shifted under the influence of the applied magnetic field H and expanded by a certain amount due to the value of H magnetic field. The inclination of the plate 3-6 relative to the axis O ₁ O _{2 of the} resonator is controlled by means of a positioning unit 3-7, containing a step motor, mechanically connected to the plate 3-6 and controlled by signals from the control unit of the complex 25. To more accurately establish a given frequency value f _{G the} laser radiation generation in LGPCH of FIG. 3 measure the frequency of generation f _G laser radiation from the output of the LGPCH 21 of FIG. 1 using the second optical frequency measurement unit 22 in FIG. 1. To this end, at the input of block 22 from the output of the LGPCH 21 of FIG. 1, a part of the generated laser radiation enters through the translucent mirror 23 and the reflective mirror 24. The second input of the optical frequency measuring unit 22 receives laser radiation from a reference laser radiation generator 17 with a reference value of the generation frequency f ₀ . Block 22 measures the frequency shift Δf = f _g -f ₀ , the value of which is digitally supplied to the control unit of the complex 25. Thus, the laser radiation frequency f _G is measured from the LGPH output relative to the reference frequency f ₀ from the reference laser radiation generator 17 :

where Δf is the actually measured value of the shift of the optical frequency f _g relative to the reference frequency f ₀ .

Next, in the control unit of complex 25, the measured value f _G is compared with the predetermined optical frequency of the LGPH laser radiation and, if they are equal, the set values of the magnetic field H are fixed using block 3-3 and the angle φ of the slope of the plate 3-6 to the resonator axis O ₁ O ₂ using the positioning unit 3-7 and then carry out the generation of laser radiation in LGPH 21 of figure 1 with a set predetermined optical frequency f _{G of the} laser radiation. If the optical frequency f _G (36) measured in block 22 differs from its value specified in block 25, the command signals are generated in the latter, according to which the updated new value of the magnetic field in the cuvette 3-1 and a new value are set in the LGPH the angle of inclination φ of the plate 3-6 to obtain a given value of the optical frequency of the generated laser radiation.

In the device of figure 1, which implements the method of laser space communication, the quantum gain of the received laser radiation is carried out by means of an active quantum filter with frequency tuning (AFCF), pos.5. Figure 4 presents a block diagram of one of the possible embodiments of the AFCF based on a photodissociation iodine laser with a spectral line tuning — the main transition of the working substance of an iodine laser [6]. Presented in FIG. 4, the AHFCR contains a cuvette 4-1 with the same active substance, atomic iodine, as the above-described LGFG in FIG. 3. The optical scheme of the AFCF contains the same as in the LGPF optical resonator formed by translucent 4-4 input and 4-5 output mirrors. The pumping unit 4-2 in the AFCHF of FIG. 4 is similar to the pumping unit pos. The control unit for the frequency of the spectral line 4-3 of FIG. 4 is similar in composition and design to the control unit for the control of the frequency of generation of poses 3-3 in FIG. 3 in LGPCH and sets a predetermined value of the magnetic field H in the cell 4-1 with the active substance. In contrast to the LGFH of FIG. 3, in the AHFH of FIG. 4, the action of the magnetic field H on the active substance in the cell 4-1 leads to a change in the frequency of the spectral line of the active substance and to some expansion of the quantum gain band of the laser radiation passing through the cell 4-1 s active substance in the AHRC. Therefore, the name of this block 4-3 of FIG. 4 reflects the function to be performed when the composition coincides with block 3-3 of FIG. 3, which performs the function of shifting the frequency of laser radiation generation in LGPH 3.

The optical plate 4-8 with the positioning unit 4-9 are similar to the corresponding elements pos.3-6, 3-7 in the LGPCH of Fig.3.

The optical plate 4-8 of FIG. 4 selects a predetermined longitudinal mode in the AFPH resonator formed by translucent mirrors 4-4, 4-5, similarly to the selection of the longitudinal mode in the LGPH resonator in FIG. 3. The selection of a given longitudinal mode in the AFCHF of Fig. 4 is carried out by changing the angle of inclination φ of the plate 4-8 relative to the longitudinal axis O ₁ O _{2 of the} AHFCF by means of a positioning unit 4-9 and setting a given angle φ by commands from the control unit of the complex 25. An additional change in the frequency of the selected the longitudinal mode in the AFCF of FIG. 4 is carried out by shifting the position on the optical axis O ₁ O _{2 of the} second output translucent mirror 4-5, which is mounted on the piezoelectric element 4-6. The latter under the action of control signals from the control unit 4-7 carries out the shift of the output translucent mirror 4-5 along the optical axis O ₁ O ₂ in one direction or another. As a result of this, a change in the optical length of the resonator occurs in the AFCF of FIG. 4, which ensures fine tuning of the selectable longitudinal mode to a predetermined value of the optical frequency of the received laser radiation. The shift of the output translucent mirror 4-5 of FIG. 4 using a piezoelectric element 4-6 by a predetermined value is carried out in accordance with the control signal received by the control unit 4-7 from the output of the control unit of complex 25 in FIG. 1. The AFCHF of FIG. 4 is additionally equipped with an acousto-optic modulator 4-10, with which additional losses are added to the AHFR cavity of FIG. 4, which impede the development of continuous generation in AHFC. The level of insertion loss is determined by the control electrical signal supplied to the electrical input of the acousto-optic modulator 4-10 from its control unit 4-11 in accordance with the control signal from the control unit of the complex 25 of Fig.1.

The quantum gain of the received laser radiation in the AFCF of FIG. 4 is as follows. Using the pumping unit 4-2 of FIG. 4, the active substance is pumped in the cell 4-1 and brought into an excited state, which provides a certain value of the gain passing through the radiation cell 4-1 in one pass. The level of additional insertion loss with the help of an acousto-optical modulator 4-10 is chosen such that, when the active substance is pumped, it provides a regenerative mode of amplification of the received radiation over several passes of radiation when it is reflected from the mirrors of the resonator 4-4 and 4-5. At the same time, the received laser radiation amplified in several passes through the output translucent mirror 4-5 is sent to the optical output of the AFPCh of Fig. 4, which is formed by the output diaphragm 4-13. In this case, the mode of radiation generation in the AFCF due to the presence of an acousto-optical (AO) modulator 4-10 is not achieved, since the AO modulator 4-10 provides the output of a part of the amplified radiation from the AFCF resonator. In the AFCHF of Fig. 4, a second super-regenerative mode of amplification of the received radiation is also possible, in which the AO modulator 4-10 is first turned off, the losses in the resonator are minimal and the generation is developed, which is periodically disrupted by pulse periodic fast switching on of the AO modulator 4-10, which ensures the introduction of losses that periodically provide a stall of generation in the cavity of the AFCRF of FIG. 4. In this mode of operation of the AHFRC, the amplification of the incoming laser radiation is carried out against the background of periodic pulsed generation of the own radiation in the AHFC; in this case, when the level of the received radiation is slightly higher than the level of intrinsic spontaneous noise, the AHFCH achieves an extremely high sensitivity with respect to the input optical signal received. A predetermined shift of the center frequency f _f of the reception and quantum gain bands in the AFCHF of FIG. 4 is carried out by setting a certain predetermined level of the transverse magnetic field H in the cuvette 4-1 using the spectral line frequency control unit 4-3 of FIG. 4, whereby widening the reception band of radiation in the AFCH and shifting the center reception band. At the same time, a certain predetermined inclination angle φ of the optical plate 4-8 is set. As a result, a certain longitudinal mode determining the magnitude of the center frequency of the radiation receiving band in the AFCHR is more accurately isolated and fixed. The final exact installation of the center frequency f _f of the radiation reception band in the AFCF is carried out by positioning and fixing the output translucent mirror 4-5 using a piezoelectric element 4-6. To accurately establish a given value of the center frequency of the reception band in the AFCHF, the natural frequency of radiation generation is measured in the AFCHF of Fig. 1 with the set values of the angle φ of the optical plate 4-8, positioning of the output translucent mirror 4-5 of Fig. 4, and with the set level of H magnetic field in the cell 4-1 and the installed pump level in block 4-2. For this short time disconnected AO modulator from its control unit 4-7, the insertion loss is reduced to a minimum level, thereby generating a laser emission own AKFPCH 5 in Figure 1 with the natural frequency f _GSS, which at this moment coincides with the the central frequency of the reception and amplification band of the radiation in the AFPCR with the previously established values of its control parameters (H, angle φ and the position of the translucent mirror 4-5). Next, they measure the optical frequency f _{soob of} this radiation, which from the output of the AFCS 5 of Fig. 1 is fed to the input of the first unit for measuring the optical frequency 12 through a translucent mirror 13 and a reflective mirror 16. The measured value of f _soob comes from the output of block 12 to the control unit of the complex 25 where f is compared with a predetermined value _GSS f _f (or the value f _f = f ₀ + Δν _c, where Δν _c - predetermined center frequency shift) is performed installed fixation AKFPCH control parameters and further to receive and quantum GAIN of the laser radiation in AKFPCH 5. mismatch setpoint f _f f from the measured value _GSS performed additional installation AKFPCH control parameters and measurement operation is repeated oscillation frequency f _GSS to obtain a result of coincidence f _GSS with a predetermined value f _p values and center frequency of the reception band of the quantum amplification in AFCHR.

As a laser generator with frequency tuning (LGPCH) and an active quantum filter with frequency tuning (AFCF) in a complex that implements the proposed method of laser space communication, it is possible to use fiber-optic laser generators (VOLG) and quantum amplifiers with tuning the frequency of visible and near IR -range. Figure 5, 6, 7 shows the block diagrams of LGPCH and AFPCH, made on the basis of fiber-optic laser technology.

Figure 5 shows a diagram of an AFFC based on a fiber optic quantum amplifier, where the following elements are indicated:

5-1 - active fiber doped, for example, with ytterbium atoms for quantum gain in the range λ = 1.2 ÷ 1.34 μm;

5-2 - optical splitter;

5-3 - semiconductor laser pumping unit;

5-4 - fiber optic Bragg grating (FBG);

5-5 - control unit parameters FBG;

5-6 - optical matching element;

5-7, 5-8 - input and output lenses.

Figure 6 shows the scheme of LGPH based on a fiber optic laser generator (VLG), where the following elements are indicated:

6-1 - active fiber;

6-2 fiber optic Bragg grating, acting as a reflector of the laser resonator;

6-3 - semiconductor laser pumping unit;

6-4 - control unit parameters FBG;

6-5 - optical matching element;

6-6 output lens.

Figure 7 shows a diagram of an AFFC made on the basis of a semiconductor laser amplifier and a fiber optic Bragg grating (FBG). 7, the following elements are indicated:

7-1 - a semiconductor laser amplifier coupled to an optical fiber 7-2;

7-2 - passive optical fiber;

7-3 - fiber optic Bragg grating (FBG);

7-4 - control unit parameters FBG;

7-5 - optical mating element;

7-6, 7-7 - input and output lenses;

7-8 - optical splitter.

Presented in FIGS. 5 and 6, fiber-optic LGPCH and AFCF are based on the use of active optical fibers as a working medium of the laser and fiber-optic Bragg gratings of refractive index (FBG) as reflective mirrors of the resonator and narrow-band optical filters. The active fibers are pumped using semiconductor (injection) lasers having a fiber output and interfaced with the active fiber through an optical splitter. Changing the generation frequency and passband of a fiber-optic narrow-band filter based on FBG (pos. 6-2, pos. 5-4, pos. 7-3) is carried out by changing the temperature of the FBG using the control unit (pos. 5-5 of FIG. 5, pos.6-4 of Fig.6 and pos.7-4 of Fig.7), which includes a Peltier semiconductor element that provides control of the temperature change of the FBG. Under the influence of FBG temperature changes, the FBG optical parameters change, which determine the frequency shift of the FBG passband and the shift of the generated LGPH frequency.

Fiber optic AFPCh has high sensitivity due to the high gain of the active fiber in a wide range of near-infrared wavelengths. FBG with controlled parameters allows you to quickly change the reception bandwidth and quantum gain of laser radiation, as well as the magnitude of the center frequency of the reception band to compensate for the Doppler frequency shift.

Presented in Fig. 7, an embodiment of the AFCF based on a semiconductor laser (optical) amplifier in the range λ = 1 ÷ 1.5 μm allows using reflective FBG 7-3 and a two-pass mode for amplifying laser radiation in a semiconductor laser amplifier pos.7-1 , 7 provide high gain of 10 ³ in the band 100-300 MHz with a center frequency rearrangement reception gain band within a few nanometers, to compensate for the Doppler frequency shifts during reciprocal motion speeds eniya base and side parts of the complex to tens km / s in the range λ = 1 ÷ 1,5 mm.

The optical frequency measuring unit (Fig. 8) is based on standard elements and nodes. On Fig shows a block diagram of a unit for measuring the optical frequency (12 and 22 in figure 1), which contains the following elements:

8-1 and 8-2 - the first and second input diaphragms;

8-3 - beam splitting element;

8-4 - photodetector;

8-5 - intermediate frequency amplifier;

8-6 - frequency meter.

The beam splitting element 8-3 sums the two optical radiation fluxes - from the output of the measured laser radiation source (LGPCH or AFPCH) and from the output of the reference laser radiation generator 17 (Fig. 1). The principle of operation of the optical frequency measuring unit is equivalent to the principle of operation of the well-known laser Doppler speed meter [18]. Photocell poz.8-4, 8 serves as an optical mixer and generates at its output a beat signal having a frequency f _and is equal to the measured shift in the optical frequency f _{L of} the laser radiation at the first input (input 1 aperture) with respect to optical frequency f ₀ of the reference oscillator laser radiation at the second input (input diaphragm 8-2, Fig. 8): f _and = f _l -f ₀ .

Then, after amplification of the signal in the intermediate frequency amplifier 8-5 is carried out measurement of the frequency f _and a frequency meter 8-6, the output of which the information in digital form the magnitude f _and corresponding value of the frequency shift Δν = f _and is fed to the control unit complex 25. The frequency meter 8-6 is a standard electronic device for measuring the frequency of an electrical signal and can be performed, for example, on the basis of a set of narrow-band resonant filters that record the frequency of the incoming electric electric signal. It is also possible to use an electronic digital frequency meter, based on the digitization of the electrical signal and counting the number of pulses filling the period of the measured electrical signal.

The multi-channel laser communication unit (BWLS), item 11 in figure 1 is an optical superheterodyne laser signal receiver with a frequency channel multiplexing at an optical carrier frequency f ₀ - the main working optical frequency of the LGPH.

Figure 9 presents the block diagram of a multi-channel laser communication containing the following elements:

9-1 - input diaphragm;

9-2 - a beam splitter;

9-3 - optical attenuator - laser local oscillator - LGPCH in the second embodiment;

9-4 - photodetector;

9-5 - the first intermediate frequency amplifier;

9-6 - radio range mixer;

9-7 - local oscillator;

9-8 - multichannel amplifier of intermediate frequencies;

9-9 - multi-channel demodulator;

9-10 - reflective mirror;

9-11 - acousto-optical modulator;

9-12 - the second input diaphragm.

This unit (BWLS) implements the reception of laser information signals by the method of laser heterodyning and converting the received signal at an optical carrier frequency into a radio frequency signal, followed by its amplification in an intermediate frequency amplifier of the radio frequency range (for example, the microwave range) and demodulating the received and amplified broadband signal with frequency channel multiplexing.

As the laser local oscillator in the first embodiment of this multichannel laser communication unit (BMS), item 11, a reference laser radiation generator, item 17, figure 1, the radiation from the output of which by means of a translucent mirror 19, figure 1 and reflective mirror 18 is used on the second optical input BMS 11 to the second input diaphragm 9-12 of Fig.9. Further, this radiation enters the optical input of the photodetector 9-4 through the acousto-optical modulator 9-11 and through the optical attenuator pos.9-3, and also comes through the reflective mirror 9-10 and the beam splitter 9-2. The acousto-optic modulator 9-11 of Fig. 9 is connected by its control input to the control unit of the complex 25. This acousto-optic modulator 9-11 serves to change (shift) the optical frequency of the laser radiation from the reference laser radiation generator 17 of Fig. 1, which is necessary to establish the necessary optical the frequency of the laser local oscillator, which, in this embodiment of the BMS, uses a reference laser radiation generator 17. The optical attenuator 9-3 of Fig. 9 serves as a controlled attenuation of the laser about radiation, which is necessary to establish the optimal laser heterodyning mode when registering with a photodetector 9-4 in Fig. 9 beatings of laser oscillator radiation from a reference laser radiation source 17 and received radiation entering the first input diaphragm, pos. 9-1 of Fig. 9 BMLS. The shift of the optical frequency and the attenuation of the laser radiation are controlled by commands from the control unit of the complex 25 of Fig. 1, received by the acousto-optic modulator 9-11 and optical attenuator 9-3 of Fig. 9. As the last used, for example, a block of optical filters moved by a stepper motor. Block 9-3 (Fig. 9) also includes an additional lens focusing the radiation into the plane of the photodetector 9-4. In the second embodiment, the BMSS 11 uses a frequency-tunable laser generator as a laser local oscillator, similar to the LGPCH of FIG. 3, item 21 of FIG. 1, the control units of which are connected to the control unit of the complex 25. This LGPCH in this second embodiment takes position 9- 3 in FIG. 9. Further, when describing the operation of the BMLS unit 11, this particular second embodiment of the laser local oscillator is given, in which the position 9-3 in Fig. 9 should be understood as LGPH, the description of which is presented in the application text and in Fig. 3.

At the same time, in the main drawing of the complex of Fig. 1, a more general case of performing BMS 11 is given, in which the reference laser source 17 is used as the laser local oscillator, and the acousto-optic modulator 9-11 of Fig. 9, controlled from the control unit, is used to shift the frequency of the laser local oscillator complex 25. The following description of the operation of the BMSL 11 reflects both of the presented embodiments of the laser local oscillator in the form of either a separate LGPCH or in the form of a reference laser radiation generator 17.

The laser radiation amplified in the AFPCh 5 of FIG. 1 is fed to the optical input of the BMS 11 through the optical filter 6 and translucent mirrors 13, 14, 15 and, accordingly, to the input diaphragm, pos. 9-1 in Fig. 9. Next, the laser radiation enters the photosensitive area of the photodetector 9-4 of Fig. 9, which performs the function of an optical range mixer. At the same time, the laser detector 9-4 receives laser radiation from the laser local oscillator 9-3 through a reflective mirror 9-10 and a beam splitter 9-2. The first intermediate frequency amplifier 9-5 amplifies the beat signal and the entire frequency band of the multi-channel signal, which can be on the order of 200-300 MHz. Next, using the mixer of the radio range 9-6 and the local oscillator 9-7 of the radio range carry out the second conversion and lowering the frequency of the received information signal. As a result of the second conversion, a multi-channel signal with frequency multiplexing of information transmission channels is formed, which is further amplified by a multi-channel amplifier of intermediate frequencies 9-8.

Next, the signals are demodulated in each of the channels using a multi-channel demodulator 9-9, from the outputs of which in digital form (or in analog form) the information goes to the information receiver unit 27 and to the control unit of the complex 25. Information from the output of unit 9-9 of FIG. .9 enters the information receiving unit 27 of FIG. 1 through the control unit of the complex 25.

As a laser local oscillator 9-3 of FIG. 9, a frequency-tunable laser generator similar to the LGPCH 21 of FIG. 1 is used. The frequency of the laser oscillator 9-3 of Fig. 9 is controlled by the signals from the control unit of the complex 25. The frequency of the laser oscillator 9-3 f _{G is} set in accordance with the following ratio:

where f _IF1 is the intermediate frequency of the first intermediate frequency amplifier 9-5 of Fig. 9, which generally lies in the microwave range and is determined by the frequency of the subcarrier of the modulating signal supplied to the laser radiation modulator 30 of Fig. 1 in the base (or, respectively, onboard) part of the complex when modulating laser radiation with an information transmitted signal; f _CR - the optical frequency of the received laser radiation.

When receiving radiation in the onboard part of the complex according to (6), f _pr is equal to:

When receiving laser radiation in the base of the complex according to

Thus, in the base and onboard parts of the complex with the same value of the intermediate frequency f _{IF 1} set different values of the optical frequency f _{g of the} laser oscillator 9-3.

When receiving radiation in the onboard part of the complex, the necessary optical frequency of the laser oscillator 9-3 f _LG2 is equal to:

When receiving laser radiation in the base part of the complex, the necessary optical frequency of the laser oscillator 9-3 f _LG1 is equal to:

This difference in the frequencies of the laser oscillator 9-3 is due to the fact that in the base part of the complex, the Doppler shift of the optical frequency is preliminarily compensated both when the laser signal (radiation) is radiated towards the side part, and when laser radiation is received from the side part of the complex by shifting the center frequency laser reception bands in the AHRC 5 of FIG. 1. In the onboard part of the complex, the reception of laser radiation and the generation of laser radiation carrying an information signal is carried out initially at a frequency f _{0 of the} working laser transition. The frequency of the laser local oscillator 9-3 is chosen equal to f _LG2 = f ₀ -f _IF1 .

Then, in the onboard part of the complex, after determining the shift of the optical frequency Δν ₂ (7), the frequency of the laser local oscillator is set equal to

As a result, accurate compensation of the Doppler shift is realized when laser radiation is received and demodulated in the multi-channel laser communication unit of Fig. 9 by laser heterodyning, in which the band and the carrier beat frequency at the output of the photodetector 9-4 of Fig. 9 exactly correspond to the intermediate frequency and the parameters of the first intermediate amplifier frequencies 9-5 of Fig. 9.

In the base part of the complex, the frequency of the laser oscillator 9-3 f _{LG1 is} immediately set in accordance with the value (39) determined by the initially measured value of the Doppler shift (1). After determining the optical shift Δν ₂ in the side part of the complex and changing the laser radiation generated in the side part of the complex and emitted in the direction of the base part of the complex in accordance with this measured shift of the optical frequency f _Г2 , the exact Doppler shift is compensated when receiving laser radiation from the side part complex in the base part of the complex, as a result of which the frequency of the laser local oscillator f _LG1 (39) set in the base part of the complex is optimal and provides full and accurate matching of the band and frequency of the beat signal at the output of the photodetector 9-4 of Fig. 9 in the base part of the complex with the frequency and parameters of the first intermediate frequency amplifier 9-5 of Fig. 9.

Next, in the base and onboard parts of the complex, using a radio frequency mixer 9-6 and a local oscillator 9-7 of Fig. 9, a second frequency conversion of the received information signal from the output of the first intermediate frequency amplifier 9-5 is performed and the signal is precisely tuned to the corresponding frequencies of the multi-channel intermediate amplifier frequencies 9-8. After that, separate demodulation is carried out in each of the channels from the output of the multi-channel amplifier of intermediate frequency 9-8 using the corresponding elements of the multi-channel demodulator 9-9 of Fig. 9.

It should be noted that in the on-board part of the complex at the first stage of laser radiation reception with the initial value of the laser oscillator frequency f _{LG2 set} in accordance with (38) due to incomplete compensation of the real Doppler frequency shift, some of the channels of the multichannel received information signal may be outside the band of highly sensitive laser radiation reception in AFCHR 5. In this case, at the first stage, only a limited amount of information can be received using the the multi-channel communication of Fig. 9 due to several channels falling into the reception and amplification band in the AHFCH 5. This is sufficient to transmit technical information from the base of the complex to the airborne part of the complex, which is necessary at the first stage to enter the space communication mode. In the second stage, after compensation of the measured amount of the shift Δν _{2 of the} optical frequency in the onboard part of the complex in the base and onboard parts of the complex, the mode of receiving the information signal in the multi-channel laser communication unit 11 of Fig. 1 is established, which ensures the transmission of a full-scale wideband signal with frequency channel multiplexing and a large amount of transmitted information relevant to the potential of the laser information signal.

The first and second photodetector blocks (FPBs) 9, 10 are made on the basis of standard two-dimensional photodetector arrays having a sensitivity range corresponding to the used wavelength λ _{0 of the} active LGSL medium. The multi-channel outputs from the FPB 9, 10 are connected via an appropriate interface to the control unit of the complex 25. The first FPB 9 is designed to receive coordinate information and determines the two-dimensional coordinates of the received laser radiation at the focus of the first lens 7, which are used in the control unit of the complex 25 to generate control signals, arriving in digital form in the OPU 3 for a more accurate direction of the axes of the receiving 1 and transmitting 4 optical antennas towards the side (or base) of the complex.

The second photodetector unit 10 is designed to receive and demodulate the received laser radiation amplified in the AFPCh 5. Each sensitive element in the FPB 10 is equipped with an electronic amplifier, the output of which is connected to the corresponding individual analog-to-digital converter. The outputs of the FPB 10 as well as pos. 9 are connected to the corresponding interfaces of the control unit of the complex 25. The FPB 10 demodulates the received laser radiation modulated by the transmitted digital signal in amplitude or polarization. For demodulation of laser radiation with polarization modulation, the FPB 10 is equipped with a polarizing optical filter installed in front of the photosensitive matrix in the FPB 10.

In this case, information is taken from that element (or group of elements) in the photosensitive matrix in the FPB 10, which is currently receiving (receiving) laser radiation received by the optical receiving antenna 1. When the received spot (laser radiation) is displaced in the focus of the lens 8 due to inaccurate pointing of the axis of the receiving optical antenna 1 to the correspondent — the airborne (base) part of the complex, the information is removed from the neighboring element (group of elements) in the FPB 10 matrix. Thus, the presence of a multi-element two-dimensional matrix in the FPB 10 gical compensates pointing inaccuracy of the optical axis of the optical reception antenna 1 to transmit a correspondent antenna (transmitter) without any additional guidance device, as in the prior art device [5].

The block for determining the motion parameters of pos. 26 in FIG. 1 contains a standard electronic computer that calculates the speed of the onboard part of the complex relative to the base part (and vice versa) according to the trajectory parameters or other data coming from the external target designation unit 29.

The motion parameter determination unit 26 is additionally equipped with a radar installed in conjunction with the optical receiving and transmitting antennas on the basic structural element pos.2 of figure 1. This radar has its own rotary support device that allows you to orient the radar sighting axis in the direction of the airborne or base parts of the complex, respectively, according to external target designation, similar to the preliminary orientation of the receiving and transmitting optical antennas. It is supposed to use a standard radar, which provides illumination of the side (base) part of the complex with electromagnetic wave radiation in the centimeter or millimeter range, reception and processing of the reflected signal, determination of spatial coordinates and radial velocity V _{1 of the} side part of the complex relative to the base part of the complex and, accordingly, the speed of the base part relative to the side of the complex [15]. The obtained information on the value of V ₁ then goes to the control unit of the complex 25.

The optical filter pos.6 of figure 1 is designed for filtering from background and interfering radiation in the ultraviolet and infrared wavelength ranges and is made of optical glass with a given characteristic of spectral transmittance and attenuation of transmitted radiation.

The control unit of the complex pos.25 in figure 1 is made on the basis of a standard computer with corresponding blocks for interfacing with the elements of the device - the base or onboard parts of the complex. In this block 25, control signals are generated that determine the operation of individual elements of the complex, as well as the distribution of the received information signals and the decision to transfer the complex to the appropriate operating mode.

.One of the options for determining (estimating) the speed of movement V _{1 of the} onboard part of the complex relative to the base part of the complex is to directly determine (estimate) in the base part of the complex the magnitude of the velocity V ₁ and, accordingly, the Doppler frequency shift Δf _d . To implement this variant of determining V ₁ at the stage of establishing space communication after the relative orientation of the antennas in the base and onboard parts of the complex, on-board parts of the complex generate laser radiation using LGPH at a frequency f ₀ - the main working frequency of the active substance used LGPH and AFCH in both parts a complex that is well known. Then, in the base part of the complex, a reception and quantum amplification of a given radiation are carried out and a frequency shift of a given received radiation is determined relative to a reference optical frequency f _{0 of a} reference laser generator 17 using the first optical frequency measuring unit 12 Δf ₀₁ . This obtained frequency shift is used to determine the speed V ₁ according to the formula

.

Accordingly, in this case, the value of the obtained estimate Δf _{01 of the} measured frequency shift is used as the value of the Doppler frequency shift Δf _d : Δf _d = Δf ₀₁ . This estimate Δf _d is then used instead of estimating the Doppler shift according to formula (1).

The determination of the speed V ₁ based on the trajectory data in the block for determining the motion parameters 26 is as follows. In block 26, from the external target designation block, pos. 29 of Fig. 1, data are received characterizing the trajectory of the onboard part of the complex, pos. 2 of Fig. 2 - the trajectory of the spacecraft pos. 4 of Fig. 2, on board of which there is an onboard part of the complex. The data are presented as an array of information S (t) = {x (t), y (t), z (t)}, which characterizes the coordinates of the onboard part of the complex, depending on the parameter t, which is a single time in the coordinate system relative to the base part of the complex. When the base part of the complex is located on the Earth’s surface, the trajectory parameters S (t) of the onboard part of the complex relative to the Earth are directly the results of calculating the motion parameters in outer space relative to the Earth of the onboard part of the complex for a single current time, which are performed in the spacecraft flight control center for each spacecraft launch into outer space and which are used to monitor the motion of the spacecraft, to monitor the performance of the spacecraft given functions of space flight and To implement space communication with the spacecraft. In the case of joint and simultaneous movement in outer space of the onboard and base parts of the complex at the spacecraft flight control center, the motion parameters are calculated separately for the onboard and base parts of the complex relative to the Earth, and the trajectory of the onboard part of the complex relative to the base part of the complex is calculated from these data (and vice versa ) As noted, this array of information S (t) = {x (t), y (t), z (t)} comes from the external target designation unit 29 to the motion parameter determination unit 26, in which the velocity vector parameters are determined by known standard algorithms V (t) the movement of the onboard part of the complex relative to the base part of the complex in the form, for example, of the corresponding derivatives with respect to time for any time t of a single time:

Next, in block 26, for any time moment t, the velocity component V _{1 of the} onboard part of the complex is determined from the mutual sight line relative to the base part of the complex based on the velocity vector V (t), characterized by three components of the velocity vector along the three axes of the Cartesian coordinate system (x, y, z). Moreover, the line of sight is known and is determined for each moment of time t by the direction cosines of the direction vector from the base of the complex to the side of the complex with coordinates {x (t), y (t), z (t)}. Next, the obtained value of the relative radial velocity V _{1 is} used to determine the Doppler shift Δf _{d of the} optical frequency.

The determination of the parameters of the trajectory of spacecraft is carried out according to well-known algorithms given in the literature on the study of the motion of space objects and satellites [16].

Thus, the determination of the speed V _{1 the} movement of the onboard part of the complex relative to the base part of the complex can be carried out in the following three ways:

1. The determination of the speed V ₁ based on a calculation based on the parameters of the trajectory of the airborne part relative to the base part of the complex.

2. Based on the determination of the speed V ₁ using a standard radar, which is part of the unit for determining the parameters of motion pos.26 figure 1.

3. Based on the determination of the speed V ₁ by measuring the shift of the optical frequency of the laser radiation emitted in the side part of the complex at a known frequency f _{0 of the} working laser transition and adopted in the base part of the complex.

Each of these methods for determining the speed V ₁ has its own advantages in establishing laser space communications in appropriate conditions. For example, when establishing long-distance space communications, it is advisable to use information about the trajectory of the onboard part of the complex relative to the base part of the complex and determine the speed V ₁ based on the calculation of the trajectory parameters obtained from the external target designation.

When establishing laser communication with a spacecraft entering the dense layers of the atmosphere when landing on Earth, it is advisable to use the definition of speed V ₁ using a radar, which is part of the unit for determining motion parameters 26.

According to the used variant of determining the speed of movement V _{1, the} block for determining motion parameters 26 may have a different composition.

The motion parameter determination unit 26 contains a standard electronic computer (PC, PC), in which the speed V ₁ is determined based on the trajectory data received from the external target designation unit 29. Additionally, a radar providing speed determination is added to the motion parameter determination unit 26 V _{1 by the} location method [15], that is, by analyzing the parameters of the signal reflected from the side of the complex when it is irradiated with this radar. Determining the speed V _{1 of the} onboard part of the complex relative to the base part of the complex, into the block 26 of which this radar is introduced, is carried out according to well-known algorithms that allow, based on the processing of the radar signal, to determine the speed V _{1 of the} located object, in this case the speed of the side of the complex [15].

The radar, which is part of the motion parameter determination unit 26 of FIG. 1, can be mounted on the base element 2 together with the receiving and transmitting optical antennas, or it can have a separate control system and is installed on the SC 32 platform of FIG. 1.

The high sensitivity of receiving information laser signals implemented in the proposed LKS complex, as well as the high noise immunity of the complex with respect to external background illumination, allows it to be effectively used to create special space communication systems.

An important area of application of the laser-space communications complex is its use for communicating with a spacecraft (SC) entering the dense layers of the atmosphere when the spacecraft land on the Earth, as well as other planets with an atmosphere, for example, on the surface of Venus, landing on the surface. Due to the high speed of spacecraft entering the atmosphere around its body, a plasma appears, which prevents the passage of electromagnetic waves in the radio range, as a result of which there is always a break in radio communications at the time of the landing of the spacecraft on Earth. This break excludes the possibility of negotiations between the spacecraft crew and the command post on Earth, and also prevents the reception of spacecraft and the transmission of telemetry information to Earth.

At the same time, electromagnetic radiation of the visible and near infrared ranges freely passes through the plasma layer formed around the spacecraft during its movement in the Earth’s atmosphere, which provides the possibility of continuous communication with the spacecraft during the entire period of its landing on the Earth’s surface.

Figure 10 shows a diagram of the organization of laser communication with spacecraft during its landing on Earth using the proposed complex of laser space communications.

Figure 10 shows the following elements of the complex laser space communications (LKS).

10-1. The base part of the LKS complex, installed on the 10-2 spacecraft in orbit around the Earth.

10-3. The receiving and transmitting optical antennas of the base part of the complex.

10-4. The unit for determining the motion parameters of the base part of the complex, containing a radar.

10-5. A spacecraft (SC), landing on the surface of the Earth 10-8 and passing through the dense layers of the Earth's atmosphere.

10-6. The onboard part of the complex of laser space communications installed onboard the spacecraft 10-5.

10-7. A porthole installed flush with the KK 10-5 case for outputting and receiving laser radiation from optical antennas of the onboard part of the laser-space communication complex.

Thus, according to the diagram shown in FIG. 10, communication with the spacecraft 10-5 landing on Earth is carried out through a spacecraft 10-2 carrying the basic part of the laser-space communication complex. KA 10-2 is in near-Earth orbit and provides relay communication with KK 10-5 through the appropriate communication channels to the Earth. It is also possible to use the basic complex of laser space communications installed on the Earth’s surface and providing laser communication with spacecraft 10-5 directly from the Earth’s surface. When carrying out laser space communication with KK 10-5, the radar included in the block for determining the parameters of motion 10-4 in the base part of the LKS complex provides the base part of the complex with information about the direction to KK 10-5 and the magnitude of the radial velocity V ₁ KK 10-5 relative to KA 10-2, which is necessary, as was shown above, to enter the laser communication mode and establish the optimal laser communication mode between the moving base and onboard parts of the LKS complex.

To reduce the weight, dimensions and energy consumption of the equipment onboard the KK 10-5, a laser generator (LG) and ACF without frequency tuning operating at a fixed frequency f _{0 were} used in the onboard part of the LKS complex. In this case, the first or second modified version of the laser space communication method discussed above is implemented. One of the options for reducing the equipment volume of the onboard part of the LKS complex is to exclude a laser generator (LG) from its composition. In this case, to transmit information from the KK 10-5 from the onboard part of the complex to the base part of the complex, a laser radiation modulator pos. 30 in Fig. 1 is used, made in a reflective design.

In this case, the laser radiation modulator 30 of FIG. 1 modulates the laser radiation from the base part of the complex, received by the transmitting optical antenna 4, which in this case acts as a receiving antenna and picks up radiation coming from the base part of the complex - from the transmitting optical antenna of the base part of the complex.

In this mode of operation of the laser radiation modulator 30, the laser radiation incident on it from the transmitting optical antenna 4 is subjected to modulation by an information signal from the block 25 and from the information source 28, then it is reflected from the mirror deposited in the form of a coating on the second outer face of the modulator 30. In reverse the modulated laser radiation passes through the transmitting optical antenna 4 and is emitted towards the base part of the complex. Thus, information is transferred from the airborne to the base part of the complex by modulating the external laser radiation (source) from the base part of the complex without using its own LGPCH. In this case, the LGPCH laser generator in the base part of the complex operates in a pulsed-periodic mode, in which part of the time the laser radiation is modulated from the LGPCH by the information transmitted signal, and the second part of the time, laser radiation is not modulated in the base part of the complex, and this laser radiation is modulated an information signal in the onboard part of the complex, after which the modulated laser radiation is reflected back towards the base part of the complex, in which the reception of this radiation using a receiving optical antenna, amplification of the radiation in the LGPH and its demodulation in the usual way in the photodetector unit 10, or in the multi-channel laser communication unit 11. Figure 11 shows a diagram of a laser radiation modulator in reflective design, where the following elements are indicated:

11-1 - laser radiation modulator, made, for example, based on an electro-optical crystal;

11-2 - reflective mirror deposited on the second face of the modulator;

11-3 - a focusing lens that focuses the received unmodulated laser radiation from the base of the complex on a reflective mirror 11-2;

11-4 - control unit of the modulator 11-1;

11-5 - reflected modulated laser radiation.

For the laser radiation modulator 30 to operate in reflective mode, an additional focusing lens (pos. 11-3) is required, which is installed between the transmitting optical antenna 4 and the modulator 30, which ensures the reflection of the radiation exactly in the direction of the radiation coming from the base of the complex. This proposed mode of operation of the laser-space communication complex without the use of an LGPCH in the on-board part of the complex of a laser generator (transmitter) is realized due to the high sensitivity of the AFCF, which reaches the ultimate single-photon quantum sensitivity limited by the quantum limit. This experimentally realized sensitivity of the AFPCR [7] allows for reliable reception of the laser information signal at the level of 2-3 photons per bit of information for a time of the order of Δτ = 3 ns at the input aperture of the receiving optical antenna.

The high noise immunity of the complex with respect to external background illumination is caused by a rather narrow optical band of reception and quantum amplification of radiation in the AFCF, which allows the reception of laser information signals against the background of such cosmic sources of background illumination as the solar disk, with practically no decrease in the sensitivity of reception of laser signals. In [17], theoretically and experimentally, the possibility of receiving laser signals using the AFCF of the LKS complex at the level of ultimate quantum sensitivity was demonstrated, at which the magnitude of the decrease in sensitivity when receiving laser signals against the background of the solar disk was no more than 12%.

One of the advantages of laser systems of space communication over space communication systems of the radio range is the possibility of using solar radiation for pumping laser generators, that is, using solar radiation to directly excite the active working substance of a laser generator - direct solar pumping. This makes it possible to reduce the amount of equipment on board the spacecraft by eliminating the sources of electrical power for pumping laser generators, and also to increase the efficiency of laser transmitters when using solar pumping to a certain extent compared with the option of using solar semiconductor batteries and generating electricity for subsequent pumping laser transmitters.

The use of direct solar pumping of photodissociation laser generators onboard a spacecraft is based on the presence in the spectrum of the solar radiation of a band of the spectrum ΔФ _H , which is effectively absorbed by the working substance of the laser, which as a result passes into an excited state that generates laser radiation.

For pumping, for example, photodissociation laser generators, the effective band of the spectrum is the band in solar radiation with a width Δ Ф _H = 250 ÷ 300 nm in the ultraviolet range with an average wavelength λ _H ≅270 nm. For this wavelength and the indicated band ΔФ _H at the level of the Earth’s orbit, the solar constant is equal to: N _λH = 0.405 · 10 ^-2 W · cm ^-2 . From this we obtain the following estimate for the pulse energy of a laser generator excited by a solar radiation flux with periodic periodic modulation of laser radiation:

where H _λ is the solar constant for the specified range ΔF _H at a distance of one astronomical unit from the Sun, that is, at the level of the Earth’s orbit; S _k , γ _k - area and efficiency of the solar collector; η is the efficiency of the active substance of the laser by optical pumping; Δt is the accumulation time of the pump radiation.

Thus, to ensure a pulsed mode of operation of a photodissociation LG with a period of T = Δt = 10 μs at an efficiency of γ _k = 0.5 and η = 0.2 with the radiation energy in the pulse

E _n = 3 · 10 ^-6 J, the required area of the solar radiation collector S _k at the level of the Earth’s orbit is S _k = 750 cm ² (d _k = 31 cm). This collector area is sufficient to provide laser communication to the boundaries of the solar system using the above parameters and the dimensions of the receiving antenna on the spacecraft D _ka = 0.5 m and the transceiving antenna in the orbit of the Earth’s satellite D ₃ = 8 m.

Thus, the use of solar pumping for direct excitation of the active substance in photodissociation LGs makes it possible to solve a number of problems in establishing long-range laser cosmic communication.

Even more effective is the use in laser space communication systems along with the AFCF of the modern near-infrared fiber-optic laser generators mentioned above (Figs. 5-7).

The high sensitivity of the AFCF of the laser-space communication complex and the presence of compensation for the Doppler frequency shift make it possible to use it for a number of fundamental physical experiments in the field of astrophysics and space research.

The following shows the possibility of using the proposed LKS complex for experimental verification of the theory of relativity by A. Einstein. On Fig presents a diagram of an experiment to test the conclusions of the theory of relativity, where the following elements are indicated. The onboard part of the complex pos.12-1 with optical receiving 12-2 and transmitting 12-3 antennas is located at point O ₁ on the axis O ₁ C. Along the axis O ₁ C with a constant speed V moves platform 12-10, at points B, C and

And _{1 of} which angular reflectors pos. 12-5, 12-6, 12-7 are installed and rigidly fixed. At point A, a beam splitting mirror is located on the AS axis, separating the laser radiation incident from the airborne portion 12-1 into two light fluxes propagating along the AS axis and in the perpendicular direction. The diaphragms 12-8, 12-9 overlap these luminous fluxes individually and allow separate reception and measurement of luminous flux parameters reflected from corner reflectors 12-6 and 12-7. Optical antennas 12-2 and 12-3 of the onboard part of the complex are oriented along the O ₁ AC axis and provide laser signals in the direction of the moving platform 12-10 and receive laser signals reflected from corner reflectors 12-5, 12-6, 12-7 .

LGPCH in the on-board part of complex 12-1 emits a sequence of short pulses - a pulse-periodic laser signal, the repetition period of which should be longer than the transit time of the pulse signal 2AC. Accordingly, the duration of a single pulse should be less than the specified radiation propagation time over a distance of 2 ° C and should separately measure the time moments of arrival of 12-3 laser pulses to the receiving optical antenna reflected from corner reflectors 12-5, 12-6, 12-7. Thus, the laser pulse emitted by the optical antenna 12-2 reaches the platform 12-10, is reflected from the corner reflectors 12-5, 12-6 and 12-7, returns back to the optical receiving antenna 12-3 and is recorded by the equipment of the airborne part 12-1 . By measuring the moments of arrival of laser pulses reflected from the indicated corner reflectors, one can judge the fulfillment of the effects predicted by the theory of relativity. In this case, the segments BA = AC, the angle BAC = 90 °, and the distance AA _{1 is} much smaller than O ₁ A, as a result of which the reflected signal from the corner reflector 12-5 can be considered to be outgoing from point A.

Consider the relationship between the reflection times of pulsed laser radiation from corner reflectors 12-5, 12-6, 12-7. The moment of arrival t _{0 of the} laser pulse from the transmitting optical antenna 12-2 to point A is equal to the time of reflection of this pulse from the corner reflector 12-5 and is the initial reference time t ₀ from the point of view of the observer in the side part of the complex 12-1, which is conditionally we consider motionless. The platform 12-10 moves with a speed V along the axis O ₁ AC relative to the side part 12-1 of Fig. 12. Next, we consider the diaphragm 12-9 closed, the diaphragm 12-8 open and consider the time t _{2 of} arrival of the laser pulse reflected from the translucent mirror 12-4 to the corner reflector 12-6 (point B) and, accordingly, the moment of reflection of this pulse back to the point BUT.

From the point of view of an observer moving with platform 12-10, this moment in time t ₂ is separated from the moment t _{0 of} arrival of the laser pulse from the onboard part to point A by the value τ = l ₀ / s, where l ₀ = BA = AC is the length segments of the platform 12-10, with - the speed of light. Accordingly, t _2B = t ₀ + τ.

From the point of view of the observer in the onboard part (stationary), the time moment t _B = t ₀ + T of the arrival of the laser pulse at the corner reflector 12-6 corresponds to the arrival of this pulse at the point in space B ₁ , since the platform 12-10 moves with speed V relative to the side part of complex 1 and during the time T = t _B -t _{0 the} distance BB ₁ = VT will pass. Hence from the triangle ABB ₁ we have:

This immediately implies the well-known relation for time dilation T from the point of view of a stationary observer in the airborne part of the complex relative to an observer moving with the platform at a speed V:

At point A, the pulse reflected from point B will come through a period of time 2T after the time t ₀ from the point of view of the observer in the airborne part of the complex:

Accordingly, in the onboard part 12-1 of the complex, this pulse will be received with a shift Δt ₀₂ in time relative to the reception of the first pulse reflected at time t ₀ from the corner reflector 12-5 by the amount:

A small addition of 2T V / s is formed by moving the platform a distance of 2TV during the pulse return time reflected from the corner reflector 12-6 back to point A. The value Δt ₀₂ is a measurable parameter that includes the known values l ₀ , V, s .

Let us further consider measuring the time of arrival at the receiving optical antenna 12-3 of the onboard part of the laser pulse complex reflected from the corner reflector 12-7. For this experiment, the diaphragm 12-8 is closed, and the diaphragm 12-9 is brought into the open state.

From the point of view of the observer moving with the platform 12-10, the time t _3C = t ₀ + τ of the laser pulse reaching the corner reflector 12-7 - point C is equal to (corresponds to) the time of arrival t _2B = t ₀ + τ of the laser pulse at point B to the corner reflector 12-6 from the time t _{0 of the} arrival of the laser pulse from the optical transmitting antenna 12-2, where, as before, τ = l ₀ / s and l ₀ = AB = AC.

From the point of view of a stationary observer in the onboard part of complex 12-1, the moment of arrival of a radiation pulse at point C t _C1 differs from the time of arrival of a laser pulse at point B (t _B = t ₀ + T) by the magnitude of the phase shift t _M in the moving coordinate system for points A and C located at a distance l _x = AC in the direction of movement of the platform with speed V:

Here l _x is the magnitude of the AC segment in the direction of the platform motion, which is a priori unknown due to the apparent decrease in the length of this AC segment and must be measured remotely by determining the arrival times of laser pulses reflected from corner reflectors 12-5 and 12-7. This simultaneous phase shift can be obtained as the time difference t _C −t _{A of the} arrival of a laser pulse emitted from the center A _{2 of the} AC segment of length l _x to its ends — points A and C from the point of view of a fixed observer. The specified time difference t _C -t _A = t _M can be obtained from the following relationships:

Hence, the moment t _C when the laser pulse reaches point C can be determined from the following relation:

At the same time, we have the ratio:

which determines the length of the path traveled by the laser pulse from point A to point C, taking into account the movement of the platform with speed V. From the last two equations we obtain a priori unknown value l _x = (АС) _{n of the} length of the AC segment - the distance between point А - a semitransparent mirror splitter 12-4 - and a corner reflector 12-7 at point C ₁ from the point of view of a fixed observer in the side part 12-1 of Fig. 12 of the complex.

Excluding the value of t _C -t ₀ , we obtain the equation for determining l _x :

- ранее определенная величина замедления (удлинения) времени платформы с точки зрения неподвижного наблюдателя в бортовой части 1 комплекса, τ=l₀/с, l₀=ВА=AC - размеры отрезков платформы 12-10 с точки зрения наблюдателя на платформе.Here

- the previously determined value of the deceleration (lengthening) of the platform time from the point of view of a fixed observer in the airborne part 1 of the complex, τ = l ₀ / s, l ₀ = BA = AC - the dimensions of the segments of the platform 12-10 from the point of view of the observer on the platform.

From here we get

which corresponds to the well-known formula for reducing the length of a moving object in the theory of relativity. Accordingly, the point in time t _C the laser pulse reaches point C and its back reflection from the corner reflector 12-7 is equal to:

In the side part 12-1 of the complex, this pulse reflected at point C from the corner reflector 12-7 will be received with a shift Δt ₀₃ in time relative to the reception of the first pulse reflected from the corner reflector 12-5 at time t ₀ by the following value :

Here, the second term is determined by the spatial displacement of point C — the corner reflector 12–7 — during the propagation of the laser pulse from point A to point C (Fig. 12), as well as the length of the AC segment itself = l _x from the point of view of a fixed observer. Taking into account

и

and

we get:

Thus, the time shift of the laser pulse Δt ₀₃ reflected from the corner reflector 12-7 at point C relative to the laser pulse reflected from the corner reflector 12-5 at point A ₁ is equal to the time shift of the laser pulse from the corner reflector 12-6 point In Fig.12 when they are received by the optical receiving antenna 12-3 in the onboard part of the complex. The formula for Δt ₀₃ and Δt ₀₂ includes all known parameters: l ₀ is the length of the segments AB = AC of the platform and V is the speed of the platform relative to the side of the complex, which can be measured when receiving laser radiation in the side of the Doppler frequency shift .

The time shifts Δt ₀₂ and Δt ₀₃ can be measured in the control unit of the onboard part of the complex 25 of Fig. 1 at the time of arrival of the laser amplitude-modulated pulses reflected from the corner reflectors of the platform 12-10 at the photodetector. A direct measurement of the indicated time shifts and a comparison of their values with theoretical values using the above formulas will make it possible to directly measure the time dilation T for a moving object and thereby experimentally verify the conclusions of A. Einstein's theory of relativity. In this case, the measurement of the time shift Δt _{03 of the} laser pulse reflected from the corner reflector 12-7 at point C should be interpreted as measuring the length l _{x of the} AC segment in the platform moving at speed V, since the reduction effect was taken into account when deriving the theoretical relation for Δt ₀₃ the length of the AC segment in a moving platform, obtained in accordance with the basic fundamental principles of the theory of relativity: the constancy and equality of the speed of light in a fixed and moving coordinate system, as well as the presence of phase shifts of moments the magnitudes for points A and C located on a straight line parallel to the velocity vector V. Thus, the proposed device — a complex of laser space communications — allows direct experimental verification of the conclusions of A. Einstein’s theory of relativity by means of high sensitivity and Doppler shift compensation in the optical wavelength range by the implementation of the experiment on location of short laser pulses of a specially made platform with angular reflectors and the measurement of time shifts of reflected and pulses using spaceborne on-board laser space communications complex.

The analysis showed that the main physical essence of the theory of relativity is the information aspect: namely, obtaining information about the parameters of a moving object by a fixed observer, that is, a special measuring process using a laser receiver of the space communication complex, which allows you to receive laser pulses, measure their parameters and interpret the received data as the effect of slowing down the speed of time and shortening lengths in a moving platform in terms of motionless about the observer. The results obtained by reducing lengths and time dilation can be interpreted as a result of distortion of information obtained under specific conditions of laser space communication as a measuring process.

As a reference, we present data on the magnitude of the change in the radiation frequency of a moving source, determined by the Doppler effect [19]. The change in the oscillation frequency perceived by the observer when the source moves at a speed V in accordance with the theory of relativity is equal to:

с - скорость света; ϑ - угол между вектором скорости и волновым вектором излучаемой световой волны; f₀ - собственная частота колебаний неподвижного источника излучения.Where

c is the speed of light; ϑ is the angle between the velocity vector and the wave vector of the emitted light wave; f ₀ is the natural frequency of oscillation of a stationary radiation source.

This formula determines both the longitudinal Doppler effect at ϑ = 0 or ϑ = π when the source moves along the line of sight, and the transverse Doppler effect at ϑ = π / 2 and the movement of the radiation source perpendicular to the line of sight. With a small value of the source’s speed V compared to the speed of light c, the transverse Doppler effect is very small, and the formula for the Doppler effect takes the following form, corresponding to the above formula (l) (ϑ = 0):

where f ₀ V / c = Δf _d is the magnitude of the Doppler shift of the optical frequency; V is the mutual velocity of the source and observer along the line of sight — the longitudinal velocity of motion.

Based on the materials of the presented method and the complex for its implementation, an experimental model of the transceiver device for laser space communication was developed, the tests of which confirmed the high efficiency of the LKS complex when implementing the regime of ultimate quantum sensitivity.

It has been experimentally shown that the sensitivity of receiving laser communication signals using an experimental model of a laser cosmic communication device created on the basis of the AFCF remains almost unchanged when a signal is received against the background of any powerful light source of natural origin. When a laser cosmic communication signal is received against a solar disk with a surface temperature of 6000 K, the sensitivity decreases by only 12% [17]. An experiment was conducted on the reception of a laser cosmic communication signal against a background of a plasma radiation source with a brightness temperature equal to 40,000 K. Figure 13 shows an oscillogram of the voltage registered in the FPB, item 9 in figure 1, of a signal against a background of a plasma source with a specified brightness temperature. Laser pulse duration τ = 40 ns; the moment of arrival of this pulse in Fig. 13 corresponds to the 13th microsecond. When recalculating the signal-to-noise ratio on a given waveform (q = 7) to q = 1, the achieved reception sensitivity is 3 photons outside the pulse of the plasma source and 6 photons against the background of the plasma source, the background pulse from which extends from the 8th to 16th waveform microseconds. Thus, the implementation of high sensitivity for receiving laser communication signals against the background of radiation from a powerful plasma source that is superior in brightness to the Sun has been experimentally proven.

On Fig presents the waveform of the signal at the output of the AHFRC when receiving a laser communication signal in the form of a pulse-periodic modulated laser signal generated by a laser transmitter - a semiconductor laser diode operating at a wavelength falling into the quantum gain band of the AHFC. The use of an AFFC with the ultimate quantum sensitivity and a semiconductor laser as a transmitter makes it possible to realize effective laser space communication in the near space zone Earth - Moon, as well as with a permanent space communication station on the lunar surface with very limited energy consumption.

On Fig presents the appearance of the active quantum filter (ACF), which is part of the experimental model of the device of laser space communications, which experimentally implemented the ultimate quantum single-photon sensitivity of the reception of laser space communication signals.

The proposed method of laser space communication and a complex for its implementation by implementing the ultimate quantum sensitivity of receiving laser information signals by means of a laser quantum amplifier (AFCF) and by providing compensation for Doppler shift on cosmic extended paths allows to achieve the following results:

- increase the range of the laser space communications complex and at the same time provide an increase in the volume and speed of information transfer (about 300 Mbit · s ^-1 ) between spacecraft and ground stations within the solar system;

- to realize the ultimate quantum sensitivity of the reception of broadband laser information signals in the conditions of long-distance space communication between fast-moving spacecraft, to realize continuous communication with the spacecraft at the moment the spacecraft enters the dense layers of the atmosphere when it lands on the Earth through the plasma layer surrounding the spacecraft;

- realize communication with the spacecraft on the background of solar radiation, for example, laser communication with the spacecraft on the surface of Mars during the confrontation of Mars with the Earth, when communication is carried out near the solar disk.

An important promising area for the use of the proposed method and complex for laser space communications is its application to solve the problem of searching for signals from extraterrestrial civilizations and establishing, after detection, continuous communication with the CC [8].

Information sources

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3. RF patent No. 2154906 from 06/28/1999, cl. Н04В, 10/00.

4. US Patent No. 5,408,351. 1995, class 359/186, H04B, 10/00.

5. RF patent No. 2111617 (05.20.1998), cl. Н04В, 10/00. Prototype.

6. Zemskov E.M., Kazansky V.M., Kutaev Yu.F., Mankevich S.K., Nosach O.Yu. RF patent No. 2133533 dated 09/30/1997. The method of spectral filtering of optical signals and a device for its implementation is an active quantum filter. - Inventions, No. 20, S.480 (1999).

7. Kutaev Yu.F., Mankevich S.K., Nosach O.Yu., Orlov E.P. Laser receiver with a quantum limit of sensitivity in the near infrared range. - Quantum Electronics, 2000, V.30, No. 9, S.833-838.

8. Kutaev Yu.F., Mankevich S.K., Nosach O.Yu., Orlov EP - Quantum electronics. 2007. Vol. 37, No. 7. C. S. 685-690. Laser transition P _3/2 -P _1/2 atomic iodine and the problem of searching for signals of extraterrestrial civilizations.

9. Kutaev Yu.F., Mankevich S.K., Nosach O.Yu., Orlov E.P. Patent No. 2248555 of the Russian Federation of 10.20.2003, the Method of determining the characteristics of the laser medium. - Inventions. 2005. No8.

10. Arzhanov V.P. et al. An iodine laser pumped with light from the front of a shock wave created by an explosive. Quantum Electronics. 1992.V.19. No. 2. S.135-138.

11. Terebizh V.Yu. Modern optical telescopes. - M .: Fizmatlit, 2005. 80 p.

12. Large ground-based optical telescopes, 10 m> D> 3 m. - http://astrotelecope.narod.ru/tele3links.html.

13. Brederlov G., Phill E., Witte K. Powerful iodine laser. // Translation from English. under the editorship of V.S. Zueva. - M .: Energoatomizdat, 1985 .-- 160 p.

14. Bourne M., Wolf E. Fundamentals of optics. // Translation from English. Ed. G.P. Motulevich. M .: Nauka, 1970, p.432.

15. Shirman Y.D. Theoretical foundations of radar. - M .: Owls. radio. 1970.

16. Fundamentals of the theory of spacecraft flight. // Under. ed. Acad. M.K. Tikhonravova. - M.: Mechanical Engineering, 1972.

16.1. Savrasov Yu.S. Methods for determining the orbits of space objects. - M.: Mechanical Engineering, 1981.

16.2. RF patent No. 2150414 dated 01.02.99. A method for determining the parameters of the orbit of spacecraft.

17. Kutaev Yu.F., Mankevich S.K., Nosach O.Yu., Orlov EP The effect of powerful background illumination on the sensitivity of an MPI with an iodine active quantum filter. - Quantum Electronics, 2002, T.32, No. 4, S.349-356.

18. Laser measuring systems. // Ed. D.P. Lukyanova. M .: Radio and communications, 1981, p. 169.

19. Physical encyclopedic dictionary. // Ed. A.M. Prokhorova. M .: Sov. Encyclopedia, 1983

Claims (11)

1. The method of laser space communication between the base and onboard parts of the complex laser space communications (LKS), including the sequential generation and modulation of laser radiation in the base and onboard parts of the complex, the mutual orientation of the transmitting and receiving optical antennas and the mutual reception of laser radiation in the base and onboard parts of the complex, characterized in that before the generation of laser radiation in the base part of the complex, the speed of movement of the onboard part of the complex relative to the base part to complex, determine the Doppler frequency shift Δf _{d of} laser radiation from the base of the complex when it is received in the onboard part of the complex, the generation of laser radiation in the base of the complex is carried out with a shift of the optical frequency Δf ₁ by a negative value of the Doppler frequency shift Δf ₁ = -Δf _d , after receiving this laser radiation in the onboard part of the complex carry out its quantum amplification, measure the shift of the optical frequency Δv _{2 of the} received and amplified laser radiation relative to the reference optical often you f ₀ , the generation of laser radiation in the onboard part of the complex is carried out with a shift of the optical frequency Δf ₂ by a negative value of the measured shift of the optical frequency Δv _{2 of the} received laser radiation Δf ₂ = -Δv ₂ , additional modulation of the generated in the side of the laser radiation is carried out by the value of the measured optical shift frequency Δv _2, followed by a reception and quantum amplification of laser radiation in the bead portion of the complex is performed with a shift of the center frequency f _p2 receiving band measured by the amount Sliding yoke Δv _{2 of the} optical frequency of the received laser radiation, after receiving laser radiation from the onboard part of the complex in the base part of the complex, it is quantum amplified with a shift of the center frequency f _f1 of the reception band by the value of the previously measured Doppler frequency shift Δf _d , the shift of Δv _{1 of the} optical frequency of the received and amplified in the base part of the complex of laser radiation relative to the reference optical frequency f ₀ , in the base part of the complex demodulate the received from the onboard part of the complex l nuclear radiation and receive information about the magnitude of the shift of the optical frequency Δv ₂ previously measured in the onboard part of the complex, on the basis of the obtained shifts of the optical frequency Δv ₁ , Δv ₂ , the parameters of the laser-space communication mode ε ₁ , ε _{2 are} determined based on the following relationships:

where Δf _d is the magnitude of the Doppler shift of the optical frequency of the laser radiation, the parameters ε ₁ and ε ₂ judge the quality of the established laser cosmic communication and under the conditions
ε ₁ ≤0.01uε ₂ ≤0.01
decide on the establishment of a regular mode of laser space communication, in which the base and onboard parts of the complex generate laser radiation, receive and quantum amplify laser radiation with previously established shifts of the optical frequencies of the generated laser radiation and with shifts of the center frequencies of the laser reception bands. 2. The method according to claim 1, characterized in that if at least one of the conditions ε ₁ ≤0.01 and ε ₂ ≤0.01 is not met, the sum of the measured values Δv ₁ , Δv _{2 is} used as the value of the Doppler shift of the optical frequency Δf _d optical frequency shifts:
Δf _d = Δν ₁ + Δν ₂ . 3. The method according to claim 1, characterized in that it determines the Doppler shift of the optical frequency Δf _{d of} laser radiation from the base of the complex when received in the side of the complex is carried out in accordance with the formula

where c is the speed of light, V ₁ is the speed of movement of the onboard part of the complex relative to the base part of the complex in the direction of the mutual sight line connecting the base and onboard parts of the complex; f ₀ is the optical frequency of the laser radiation generated in the base part of the complex and corresponding to the optical frequency of the working quantum transition of the active substance used in the generation of laser radiation and in the implementation of quantum amplification of laser radiation in the base and side parts of the complex. 4. The method according to claim 1, characterized in that the optical frequency of the active quantum transition of the active substance used in the generation of laser radiation and quantum amplification of laser radiation in the base and side parts of the complex is adopted as the reference optical frequency f _{0 of the} laser radiation. 5. A complex of laser space communications (LKS), consisting of identical base and airborne parts located on different spacecraft (SC), each of which contains a receiving and transmitting optical antenna mounted on the base element and rigidly connected to it, supporting-rotary a device (OPU) kinematically connected to the base element, an optical filter, the first and second photodetector blocks (FPB), a laser radiation modulator with a control unit, a unit - an information source and a unit - an information receiver, a control unit of the complex, the control input of the control amplifier, the outputs of the first and second FPBs, the information receiver block and the information source block are connected to the complex control unit, the laser radiation modulator control unit is connected to the complex control unit, characterized in that an active component is introduced into each of the identical parts of the complex frequency tunable quantum filter (AFCF), frequency tunable laser generator (LGPF), multichannel laser communication unit, first and second optical frequency measurement units, reference generator azeri radiation, a block for determining motion parameters, the first and second lenses, three reflective mirrors and six translucent mirrors, while the optical input of the AFFC is connected to the optical output of the receiving optical antenna, the optical output of the AFFC is connected to the optical input of the first FPB through an optical filter, the first translucent mirror and the first lens, and with the optical input of the second FPB through the optical filter, the first and second translucent mirrors and the second lens, additionally, the optical output of the AFFC is connected to the optical inputs a multichannel laser coupling and the first optical frequency measurement unit through an optical filter and the first, second, third translucent mirrors and the first reflective mirror, the LGPH optical output is connected to the optical input of the transmitting optical antenna through a laser radiation modulator and to the optical input of the second optical frequency measurement unit by the sixth translucent mirror and the third reflective mirror, the optical output of the reference laser radiation generator is optically coupled to the second optical the inputs of the second optical frequency measuring unit, the first optical frequency measuring unit by means of the fourth and fifth translucent mirrors, and the multi-channel laser communication unit through the fourth, fifth translucent mirrors and the second reflective mirror, while the control inputs of the AHFPC and LGPH are connected to the control unit, the inputs of which connected to the first and second blocks for determining the optical frequency and to the multi-channel laser communication unit, the output of the unit for determining motion parameters is connected to the unit board and to the output of the external target designation unit. 6. The LKS complex according to claim 5, characterized in that it contains an active quantum filter with frequency tuning (AFCF) that contains optically coupled input diaphragm, input translucent mirror, a cell with transparent input and output windows and active substance, sequentially mounted on the optical axis and pump unit, an optical plate with a positioning unit, an acousto-optical modulator with a control unit, a translucent output mirror, a piezoelectric element with a control unit connected to a translucent output mirror, a control unit the frequency of the spectral line connected to the cell with the active substance, while the control inputs of the pump unit, positioning unit, acousto-optic modulator control unit, piezo element control unit and spectral line frequency control unit are connected to the complex control unit. 7. The LKS complex according to claim 5, characterized in that it has a frequency-tunable laser generator (LGPF) that contains optically coupled output diaphragm, a translucent resonator mirror, a cuvette with an active substance, a pump unit, and a generation frequency control unit connected to the cell with the active substance, an optical plate with a positioning unit, a reflective mirror of the resonator, while the control inputs of the pump unit, the control unit of the generation frequency and the positioning unit connected to the control unit of the complex. 8. The LKS complex according to claim 5, characterized in that the multichannel laser communication unit comprises a photodetector, a first intermediate frequency amplifier, a radio frequency mixer with a local oscillator, a multi-channel intermediate frequency amplifier, a multi-channel demodulator, and optically coupled optical attenuator and acousto-optical a modulator, the input of the optical attenuator by means of a reflective mirror and a beam splitter is optically connected to the optical input of the photodetector, and the input is acousto-optical of the modulator is optically connected to the output of the reference laser generator by means of reflective and translucent mirrors, the control electric input of the optical attenuator and the control input of the acousto-optical modulator are connected to the output of the complex control unit, the output of the multi-channel demodulator is connected to the input of the complex control unit. 9. The LKS complex according to claim 5, characterized in that it has an active quantum filter with frequency tuning (AFCF) made on the basis of a fiber-optic quantum amplifier containing an active optical fiber, the input of which is through an optical splitter and the first fiber-optic Bragg grating optically connected to the input lens, and the output of which through the second fiber optic Bragg grating is optically connected to the output lens, the second input of the optical splitter is connected to the semiconductor laser pumping unit First and second fiber Bragg gratings (FBGs) are connected to the parameter control unit. 10. The LCS complex according to claim 5, characterized in that the frequency-tunable laser generator (LHF) contains an active optical fiber, the input of which through the first fiber-optic array is optically coupled to the semiconductor laser pumping unit, and the output is optically coupled through the second fiber optic grating with an input lens, the first and second fiber optic gratings are connected to the parameter control unit. 11. The LKS complex according to claim 5, characterized in that it comprises an active quantum filter with frequency tuning (AFCF) containing a semiconductor laser amplifier coupled to an optical fiber, the optical input of which is connected to the input and output lenses through an optical splitter and coupling elements, and the optical output is connected to a fiber optic Bragg grating connected to the parameter control unit.

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