RU2221981C2 - Laser device for monitoring of efficiency of measures taken for protection of rooms against unauthorized pickup of vocal information - Google Patents

Abstract

FIELD: protection of rooms against unauthorized pickup of vocal information. SUBSTANCE: the laser device has a forming receiving optical system that is optically connected to the input of the receiving active optical fiber whose output is electrically is connected to the input of a photodetector electrically whose output is connected to the input of the information listening unit via series-connected second amplifier, demodulator, amplifier. The laser output is optically connected to the input of the transmitting active optical fiber, whose output is optically connected to the forming transmitting optical system. The optical glass with a reticule is mechanically connected to the forming transmitting and receiving optical systems, and the power unit is connected to the inputs of the photodetector, second amplifier, demodulator, amplifier, information listening unit. The device body may be made in the form of a rim of glasses. EFFECT: expanded functional potentialities of the device and enhanced operativeness of estimation of the efficiency of the measures taken. 2 cl, 2 dwg

Description

 The proposed device relates to the field of optics, in particular to devices of measuring equipment, and can be used to monitor the effectiveness of measures to protect the premises from unauthorized removal of speech information.

 Separate optical devices are known for evaluating the values (parameters) of optical radiation characterizing the degree of protection of the premises from unauthorized removal of speech information, which use the principle of direct contact, i.e. installation of an acoustic or other sensor in the room (see, for example, the journal Special Technique, 2001, 6, p. 54-59).

 The disadvantage of such devices is mainly the inability to conduct covert control, which can often lead to incorrect estimates of the effectiveness of the measures taken.

 Known devices operating on a contactless principle. Such devices use laser or other radiation, which is sent to the room and assessed the ability to pick up voice information.

 Closest to the proposed device is a laser acoustic location system type STG-5410-LASR, described in the book A. Khorev. Technical means and methods of industrial espionage. M., 1997, p. 80-82, 163, adopted as a prototype.

Figure 1 shows the functional diagram of the device of the prototype, where indicated:
1 - optical sight;
2 - laser;
3 - photodetector;
4 - demodulator;
5 - amplifier;
6 - block listening information;
7 - power supply;
8 - housing.

 The prototype device has the following functional relationships.

 An optical sight 1, a laser 2 and a photodetector 3 are rigidly fixed on the housing 8, and electronic units are installed inside the housing: a demodulator 4, an amplifier 5, an information listening unit 6, and a power supply 7.

 The prototype device operates as follows.

 Using the optical sight 1, the operator directs the laser radiation at the object 2. The laser radiation reflected from windows or other reflective surfaces is captured by the photodetector 3. Then, the optical (laser) radiation is converted by the demodulator 4 into electrical signals, which, after amplification by the amplifier 5, enter the information listening unit 6.

 The disadvantage of the prototype device is that for aiming the laser beam and the photodetector, a rigid support is required, for example, a tripod, which eliminates the stealth of control, as well as the complexity and inconvenience of operational monitoring from various points.

 To eliminate these drawbacks, an optical glass with a grid, a second amplifier transmitting an active fiber, forming a transmitting optical system, and a receiving active optical fiber are introduced into a laser acoustic location system containing a laser, a photodetector, a demodulator, an amplifier, a power listening unit, and a housing; forming receiving optical system. In addition, the device case is made, for example, in the form of a spectacle frame, in which optical glass with a grid is rigidly fixed, and the transmitting and receiving active optical fibers with forming optical systems are mounted in the form of arches. The optical axis of all optical systems are installed in space in parallel.

 This allows you to expand the functionality of the device and increases the efficiency of evaluating the effectiveness of ongoing activities.

In FIG. 2 shows a functional diagram of the proposed device, where the following notation is introduced:
1 - optical glass with a grid;
2 - laser;
3 - transmitting active optical fiber;
4 - forming transmitting optical system;
5 - photodetector;
6 - receiving active optical fiber;
7 - forming receiving optical system;
8 - second amplifier;
9 - demodulator;
10 - amplifier;
11 - block listening information;
12 - power supply;
13 - case.

 The proposed device has the following functional relationships.

 In the case 13, made, for example, in the form of a spectacle frame, optical glass with a grid 1 is rigidly fixed, and the transmitting active optical fiber 3 with the forming optical system 4 and the receiving active optical fiber 6 with the forming receiving system 7 are mounted in the form of arches. Moreover, the optical axis of the optical glass with a grid 1 of the forming optical systems 4 and 7 are installed so that they are parallel in space.

 The output of the laser 2 is optically connected to the input of the transmitting active optical fiber 3, the output of which is optically connected to the forming transmitting optical system 4, which is the output of the device.

 The input of the photodetector 5 is optically connected to the output of the receiving active optical fiber 6, the input of which is optically connected to the forming receiving optical system 7, which is the input of the device.

 The output of the photodetector 5 is electrically connected to the input of the second amplifier 8, the output of which is electrically connected through a series-connected demodulator 9, the amplifier 10 with the input of the information listening unit 11.

 The output of the power supply 12 is electrically connected to the inputs of the information listening unit 11, amplifier 10, demodulator 9, second amplifier 8, photodetector 5 and laser 2.

As a result of this, three optical channels coordinated in space are realized in one device:
a transmitter (including a laser 2 transmitting an active optical fiber 3 and forming a transmitting optical system 4);
a receiver (photodetector 5, receiving active optical fiber 6, forming a receiving optical system 7);
optical sight (optical glass with a grid 1).

 Since optical glass with a grid 1 and the forming transmitting and receiving optical systems 4 and 7 are mechanically fixed in the casing and installed so that their optical axes are oriented parallel in space, it turns out that all the channels work on the same object.

 The proposed device operates as follows.

 Observing through an optical glass with a grid, the operator selects the desired room and its vulnerable points (windows, slots, doors, etc.), and then directs the laser and photodetector to the selected point. After that, he turns on the laser. Laser radiation through a transmitting active optical fiber enters the input of the forming optical system. At the output of the optical system, a beam is formed with a given radiation pattern and sent to the same point where the operator is looking. The reflected laser radiation modulated by the sound (speech) frequency is captured by the receiving optical system and sent through the active optical fiber to the input of the photodetector, where the optical radiation is converted into electrical signals corresponding to the modulation speech frequency. The amplifier pre-amplifies the signals received at the input of the demodulator. The allocated sound frequencies are amplified and fed to the information listening unit.

 Active optical fibers serve to reduce losses in the transmission of optical signals.

 The presence of a reticle in the optical glass allows you to direct the transmitter and photodetector with sufficient accuracy (at least half the mesh stroke). Usually this value does not exceed one arc minute.

 The introduction of optical glass with a grid and transmitting and receiving active optical fibers with forming optical systems provides stable, continuous, operational and attention-saving control over the effectiveness of measures to protect premises from unauthorized removal of speech information.

 The implementation of the proposed device does not cause difficulties, since all the individual blocks and nodes included in it are well known, widely described in the technical literature and can be used to perform the proposed device without additional development.

Claims (2)

1. A laser device for monitoring the effectiveness of measures to protect the premises from unauthorized removal of voice information, containing a laser, a photodetector, a demodulator, an amplifier, an information listening unit, a power supply and a housing, characterized in that optical glass with a grid, a second amplifier are inserted into it, transmitting active optical fiber, receiving active optical fiber, forming a transmitting optical system and forming receiving optical system, optically connected to the input of the receiving active optical fiber, the output of which is optically connected to the input of the photodetector, the output of which is electrically connected through a second amplifier, demodulator, amplifier with the input of the information listening unit, and the laser output is optically connected to the input of the transmitting active optical fiber, the output of which is optically connected to the forming transmitting optical system, while the optical glass with a grid is mechanically connected to the forming transmitting and receiving optical systems, and the power supply connected to the inputs of the laser, photodetector, second amplifier, demodulator, amplifier, information listening unit. 2. The laser device according to claim 1, characterized in that the body of the device is made, for example, in the form of a spectacle frame, the optical glass with a grid being rigidly fixed in the frame, and the transmitting and receiving active optical fibers are made in the form of spectacle frame arches and are fixed in at the points of connection of the arches of glasses, and the forming transmitting and receiving optical systems are fixed at the places of connection of the arches, while the laser, power supply, photodetector, second amplifier, demodulator, amplifier and information listening unit are mounted in the earhooks of the glasses oic rim.

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