RU2630531C1 - Method of compensating for thermal bending and deformation of laser gyroscope monoblock optical channels - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method of compensating for the thermal bending and deformation of polygonal laser gyroscope monoblock optical channels is based on the installation of an optically transparent monoblock, the operating mode of which is achieved using a micro-power semiconductor laser diode equipped with, at least, one Peltier element for the thermostabilization of the radiation regime of a laser diode located inside the optical circuit, formed by a set of optical laser gyroscope channels, on a metal base with functions on a cooling radiator. At the same time, in the amount of, at least, two to the optical channel, grooves of a given depth and geometry are created in the metal base, forming convex zones in the metallic base, which are in thermal contact with the bottom surface of the polygonal monoblock relative to the local heating source - the Peltier element and provide zone equalization of the temperature gradient in the working zones, which ensures compensation of the thermal imbalance of the optical channel working zones in the amount equal to the amount of the generated convex zones. The contour of the polygonal monoblock is covered by a groove of a given depth and geometry to exclude the general influence of the metal base on the temperature distribution in the convex zones and to provide the required temperature gradient in the compensation zone with respect to the local heating source.

EFFECT: compensation for thermal bending and deformation of the polygonal laser gyroscope monoblock optical channels and ensuring its operability at high and low ambient temperatures.

3 dwg

Description

The invention relates to the field of laser technology and can be used to create navigation systems, in particular in strapdown inertial navigation systems.

A technical solution is known, developed by the American company Honeywell (I. Gorenstein, I. A. Shulman. Inertial navigation systems. Edited by I. A. Gorenstein, Candidate of Technical Sciences - Moscow: Mechanical Engineering, 1970, pp. 161-230 ) Structurally, the system contains a housing, anodes, mirrors with high reflectivity, cylindrical channels, a cathode, a diaphragm, a translucent mirror, a prism. The body of the device is a monolithic polygonal block of fused quartz in the form of a twelveagon with irregular sides, in which cylindrical channels are drilled. The axes of these channels lie in the same plane and form an equilateral triangle, at the vertices of which there are mirrors.

The monoblock is mounted across the entire plane on a metal base with the functions of a cooling radiator to create an angular velocity sensor for an inertial navigation system. To improve thermal conductivity, a heat-conducting paste can be applied to the surface of the radiator in the interface zone with the monoblock.

Disadvantage. Since the casing of the device is made in the form of a hexagon with irregular sides, a significant temperature error arises due to uneven heating from the radiation source, which consists in an uneven change in the length and diameter of the optical channels, leading to bending and deformation of the optical channels. This leads to a significant narrowing of the range of its performance at high and low ambient temperatures.

The use of a common cooling radiator according to a known scheme does not solve this problem.

Closest to the claimed device is a monoblock design of a laser gyroscope (Application for invention of the Russian Federation No. 2014154547 dated 12/31/2014, IPC: G01C 19/66, applicant: OAO ELARA Scientific and Production Complex named after G. Ilyenko (g. Cheboksary), Russian Federation (RU).

An assembly drawing of a monoblock laser gyro is shown in FIG. 1. The following notation is accepted here:

1 - polygonal monoblock in the form of a base;

2 - optical channels;

3 - mirror full reflection of radiant energy;

4 - a translucent mirror in the form of an interference

converter;

5 - a source of optical radiation - a semiconductor laser;

6 - external optical resonator;

7 - reflective coating;

8 - optically transparent hole of the external optical resonator;

9 is a longitudinal optical channel of an external optical resonator;

10 - thermoelectric module with a radiator and a Peltier element;

11 is the geometric center of the optical monoblock;

12 - equilateral regular hexagon;

13 - end face of the monoblock hexagon;

14 - a fixing element;

15 - sleeve;

16 - clamping elements;

17 - the periphery of the monoblock;

18 - quotation device;

19 - sleeve for mounting a monoblock to a metal

base / radiator.

The laser gyroscope contains a polygonal optically transparent monoblock 1 with formed optical channels 2, an optical strapping circuit 3.4 for implementing the Sagnac effect and acquiring information about the angular velocity of object 4, and a micropowerful semiconductor laser diode 5 is included in the design as a source of radiation. Structurally, the source optical radiation is made in the form of a thermoelectric module 10, consisting of an external radiator and at least one Peltier element, located geometrically m in the center of the optical monoblock 1. In fact, the thermoelectric module 10 is also a monoblock heating source located inside the optical circuit formed by the set of optical channels 2 of the laser gyroscope. Such a constructive solution provides linear thermal expansion from the center to the periphery over the entire volume of the monoblock, which eliminates significant bending and deformation of the channels of the monoblock and optical strapping at small temperature gradients: a system of mirrors 3 and interference converter 4. In this case, the change in the internal diameter of the optical channel does not exceed 25-30% and does not affect the distortion of optical flows, which ensures the normal mode of the optical gyroscope.

The monoblock provides for the possibility of its installation using the mounting bushings 19 on a metal base 20 over the entire plane with the functions of a common cooling radiator, which is part of the angular velocity sensor of the inertial navigation system. To improve thermal conductivity, a heat-conducting paste 21 can be applied to the surface of the radiator in the interface zone with the monoblock.

A generalized diagram of a monoblock laser gyro from the point of view of the distribution of temperature fields in the design of the prototype is presented in FIG. 2. Here, the monoblock 1 is placed on a metal base 20 with the functions of a cooling radiator. A thermoelectric module with a radiator and a Peltier element is presented as element 10. To improve thermal conductivity, a heat-conducting paste 21 is applied to the surface of the radiator in the interface with the monoblock. Due to the fact that both the material of monoblock 1 (organic glass) and the base material 20 (metal) have linear thermal conductivity, then the middle of the optical channels 2 and their ends from the heat source are at different distances, which leads to the appearance of a significant temperature gradient when operating in a wide range e temperatures and negative effects on optical channels.

Disadvantage. With significant temperature gradients that occur when the laser gyro is operating in a wide temperature range, a significant temperature difference occurs in the middle and at the edges of the optical channels of the optical circuit. This leads to thermal bending and deformation of the optical channels in excess of 30% and, as a result, a violation of the propagation conditions of the optical flows, leading to the appearance of the Sagnac effect due to additional reflections in each optical channel.

The use of a common cooling radiator according to a known scheme does not solve this problem.

The technical result of the invention is to develop a method of compensating for thermal bending and deformation of the optical channels of a monoblock laser gyroscope and ensuring its operability at high and low ambient temperatures.

The technical result is achieved in that the polygonal monoblock of the laser gyroscope is mounted on a metal base with the functions of a common cooling radiator. The operating mode of the monoblock is ensured by the use of a micropowerful semiconductor laser diode equipped with at least one Peltier element for thermal stabilization of the radiation mode of the laser diode. At the same time, a micropowerful semiconductor laser diode is a thermoelectric module and a monoblock heating source. In constructive terms, the heating source is actually located inside the optical circuit formed by the set of optical channels of the laser gyroscope, and the monoblock itself, in order to improve the temperature regime of the device, is mounted on a metal base. In a first approximation, the heating source is located symmetrically relative to the optical channels of the optical circuit of the monoblock.

When starting up the device, a micropowerful semiconductor laser diode at a working emitter power of 100-250 mW gives a certain amount of heat to a monoblock made, for example, of organic glass with open leaky optical channels. To ensure compensation for the temperature imbalance of the working zones of the optical channels of the monoblock, and in fact, compensation of thermal bending and deformation of the optical channels of the monoblock, special grooves of a given depth and geometry are formed in the metal base in the amount of at least two per optical channel, which form convex in the metal base zones. They are in thermal contact with the bottom surface of the polygonal monoblock relative to the local heating source - the Peltier element and provide zonal alignment of the temperature gradient in the working areas. This provides compensation for the temperature imbalance of the working zones of the optical channels in an amount equal to the number of formed convex zones. To exclude the general effect of the metal base on the temperature distribution in convex zones, the contour of the polygonal monoblock is covered by a special groove of a given depth and geometry, which provides the required temperature gradient in the compensation zone with respect to the local heating source.

Common to the proposed method and prototype are the following features:

- a polygonal monoblock of a laser gyro with an optical circuit formed by at least three optical channels;

- the heat source for the monoblock is a micromous semiconductor laser diode equipped with at least one Peltier element for thermal stabilization of the radiation mode of the laser diode;

- the heat source is structurally located inside the optical circuit formed by a set of optical channels;

- the monoblock is mounted on a metal base with the functions of a common cooling radiator to facilitate the temperature regime.

Distinctive from the prototype are the following features:

- in the metal base are created, in an amount of at least two per optical channel, special grooves of a given depth and geometry, forming convex zones in the metal base;

- convex zones formed in the metal base are in thermal contact with the lower surface of the polygonal monoblock relative to the local heating source - the Peltier element and provide zonal alignment of the temperature gradient in the working zones;

- the number of formed convex zones determines the number of working zones of the optical channels, where the temperature imbalance is compensated;

- the contour of the polygonal monoblock is covered by a special groove of a given depth and geometry to exclude the general effect of the metal base on the temperature distribution in convex zones and to provide the required temperature gradient in the compensation zone with respect to the local heating source. The essence of the method, its feasibility and the possibility of industrial application is illustrated by the generalized scheme of a monoblock laser gyroscope, which reflects the distribution of temperature fields in the design shown in FIG. 3.

The polygonal monoblock 1 of the laser gyroscope is mounted on a metal base 20 with the functions of a common cooling radiator. The operating mode of the monoblock is ensured by the use of a micropowerful semiconductor laser diode equipped with at least one Peltier element for thermal stabilization of the radiation mode of the laser diode and which is a thermoelectric module 10. In a structural plan, the heating source is actually located inside the optical circuit formed by the set of optical channels 2 of the laser gyroscope. In a first approximation, the heating source 10 is located symmetrically relative to the optical channels 2 of the optical circuit of the monoblock 1.

When the device is started, a micropowerful semiconductor laser diode with a working emitter power of 100-250 mW gives a certain amount of heat to a monoblock 1, made, for example, of organic glass (grade СО-120-К GOST 10667-90), with open leaky optical channels 2. For providing compensation for the temperature imbalance of the working zones of the optical channels 2 of the monoblock 1, and in fact, compensation of thermal bending and deformation of the optical channels 2 of the monoblock 1, in the metal base 20 (alloy AL-2 - AL-8) are created, in the amount of at least two optical path grooves predetermined depth and geometry which is formed in the metal base convex zone. They are in thermal contact with the lower surface of the polygonal monoblock 1 relative to the local heating source - the Peltier element and provide zonal alignment of the temperature gradient in the working areas of the optical channels 2. This ensures that the temperature imbalance of the working areas of the optical channels 2 is compensated in an amount equal to the number of convex zones formed. In this case, the contour of the polygonal monoblock 1 is covered by a special groove of a given depth and geometry to exclude the general effect of the metal base 20 on the temperature distribution in convex zones, which will ensure the creation of the required temperature gradient in the compensation zone with respect to the local heating source.

The technical solution underlying the method does not explicitly follow from the prior art. In addition, in the process of patent search did not reveal technical solutions having features that match the distinctive features of the claimed method.

The claimed method has significant differences from the closest analogues and meets the criterion of patentability of the invention - "novelty."

The claimed method is technically feasible and industrially implemented at the instrument-making enterprise. The tests carried out confirm the achievement of the claimed technical result of the developed method - compensation of thermal bending and deformation of the optical channels of the monoblock laser gyroscope and ensuring its operability at high and low ambient temperatures.

In connection with the foregoing, the materials of the application for the proposed invention meet the criteria of patentability and industrial applicability.

Claims (1)

The method of compensating for the thermal bending and deformation of the optical channels of a polygonal monoblock laser gyroscope is based on the installation of an optically transparent monoblock, the operating mode of which is achieved using a micropowerful semiconductor laser diode equipped with at least one Peltier element for thermal stabilization of the radiation mode of the laser diode located inside the optical circuit formed by optical channels of a laser gyroscope, on a metal base with the functions of a common p cooling radiator, characterized in that at least two per optical channel are created in the metal base, special grooves of a given depth and geometry, forming convex zones in the metal base that are in thermal contact with the bottom surface of the polygonal monoblock relative to the local heating source - Peltier element and provide zonal alignment of the temperature gradient in the working areas, which provides compensation for the temperature imbalance of the working areas of the optical channels in an amount equal to the number of convex zones formed, while the contour of the polygonal monoblock is covered by a special groove of a given depth and geometry to eliminate the general effect of the metal base on the temperature distribution in the convex zones and to provide the required temperature gradient in the compensation zone with respect to the local heating source.

Images