Active cavity adjusting device for laser gyroscope
The active cavity adjustment device gradually adjusts the position of the gain laser tube and mirror to determine the optimal resonant optical path, which solves the problem of inaccurate measurements under low losses in traditional cavity adjustment methods, and realizes efficient cavity adjustment and performance optimization of laser gyroscopes.
Patent Information
- Application Number
- CN202422802430.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-15
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2034-11-15
AI Technical Summary
The traditional laser gyroscope cavity adjustment method is difficult to accurately measure cavity loss under low losses, which makes it difficult to judge the cavity effect, affecting the high-precision performance and production pass rate of laser gyroscopes.
An active cavity adjustment device including the first and second gain laser tubes, a photodetector and a plurality of reflectors is adopted. By gradually adjusting the positions of the gain laser tubes and reflectors, the optimal resonant optical path is determined and replaced with a spherical mirror, an efficient and accurate cavity adjustment process is achieved.
The efficient and accurate cavity adjustment of the laser gyroscope is achieved, the performance of the laser gyroscope is optimized and the production efficiency is improved, and the path uncertainty caused by the simultaneous adjustment of multi-spherical mirrors is avoided.
Smart Images
Figure CN223243642U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of laser gyroscope preparation, in particular to an active cavity adjustment device of a laser gyroscope. Background Art
[0002] The laser gyroscope (LGG) is a high-precision inertial device with extensive applications in both military and civilian fields. Its principle is to measure angular velocity using the optical path difference, also known as the Sagnac effect. In a closed optical path, two beams of light emitted by a light source, traveling clockwise and counterclockwise, interfere with each other. By detecting the phase difference or changes in the interference fringes, the angular velocity of the closed optical path can be measured. The key component in a LGG that produces the Sagnac effect is the ring laser resonator, and the quality of its alignment directly affects the overall performance of the LGG.
[0003] Traditional laser gyro cavity tuning methods generally involve aligning the light beam with the center of the optical path hole axis and measuring the cavity loss. First, with the help of the laser gyro's visual inspection system, the cavity tuner can adjust the resonant cavity while observing the relative position of the light beam and the aperture until the light beam is located at the center of the optical path hole axis, thereby achieving coarse alignment. Fine alignment is achieved by measuring the cavity loss and adjusting the spherical mirror in real time. The smaller the cavity loss, the better the cavity tuning effect. There are usually two methods for measuring cavity loss: the resonance method and the time decay method. The resonance method is to inject a laser with a linearly changing frequency into the ring laser resonant cavity, use a photodetector to receive the transmitted light wave signal, and draw a light intensity spectrum line diagram. The spectrum line is in the form of Lorentz, and its half-height width is proportional to the ring laser resonant cavity loss. The loss can be obtained by measuring the half-height width of the spectrum line. However, this method is not suitable for measurements when the loss is lower than 500ppm, because the shape of the spectrum line deviates from the Lorentz line shape, and the half-height width at this time can no longer represent the cavity loss. The time-decay method uses an acousto-optic switch to rapidly cut off the light source at a light intensity threshold. The cavity loss is then estimated by measuring the time it takes for light to dissipate within the cavity. However, this ring-down time is affected by various factors, such as ambient temperature. These factors can cause fluctuations in the ring-down time, leading to inaccurate measurement results and difficulty in assessing the effectiveness of cavity tuning. Traditional cavity tuning methods and devices have proven ineffective in ensuring the proper tuning of laser gyros, impacting the performance and production yield of high-precision laser gyros. Utility Model Content
[0004] In view of the problems in the background technology, the present invention proposes a laser gyroscope active cavity tuning device which can efficiently and accurately complete the laser gyroscope cavity tuning.
[0005] The utility model adopts the following technical solutions:
[0006] A laser gyro active cavity tuning device, comprising:
[0007] a first gain laser tube, a second gain laser tube, a photodetector, a first reflector, a second reflector, a third reflector and a fourth reflector,
[0008] The first gain laser tube is placed on the left side of the cavity to be adjusted, and corresponds to the upper left corner of the cavity to be adjusted. The first reflector is placed on the left side of the first gain laser tube. The second gain laser tube is placed on the left side of the cavity to be adjusted, and corresponds to the lower left corner of the cavity to be adjusted. The second reflector is placed on the left side of the second gain laser tube. The photodetector is placed below the cavity to be adjusted, and corresponds to the lower right corner of the cavity to be adjusted. The third reflector is placed below the cavity to be adjusted, and corresponds to the lower left corner of the cavity to be adjusted. The fourth reflector is placed above the cavity to be adjusted, and corresponds to the upper left corner of the cavity to be adjusted.
[0009] Preferably, it also includes a collimating laser, a second aperture and a third aperture,
[0010] The collimating laser is placed on the right side of the cavity to be adjusted, corresponding to the lower right corner of the cavity to be adjusted. The second aperture is placed between the first gain laser tube and the cavity to be adjusted, and the third aperture is placed between the second gain laser tube and the cavity to be adjusted.
[0011] Preferably, the method further comprises: a first diaphragm, wherein the first diaphragm is arranged between the cavity to be adjusted and the collimating laser.
[0012] Preferably, the first reflector is a plane reflector, the second reflector is a curved reflector, the third reflector is a plane reflector, and the fourth reflector is a curved reflector.
[0013] Preferably, the first reflector is a curved reflector, the second reflector is a plane reflector, the third reflector is a curved reflector, and the fourth reflector is a plane reflector.
[0014] Preferably, one of the first gain laser tube and the second gain laser tube is a gain laser tube with a Brewster window.
[0015] Preferably, the other of the first gain laser tube and the second gain laser tube is a gain laser tube with an anti-reflection film.
[0016] Compared with the prior art, the advantages of the present invention are:
[0017] The laser gyro active cavity tuning device of the present invention uses two gain laser tubes and a gyro cavity to form an active cavity. Three plane mirrors on the cavity to be tuned (two plane mirrors on the cavity to be tuned and one temporary adjustment plane mirror) and corresponding gain tubes can be used to determine an optimal resonant optical path. Specifically, the point of maximum resonant light intensity in the resonant optical path, i.e., the optimal position of the lens, is found. The temporary adjustment plane mirror in the optical path is then replaced with a spherical mirror, and the optimal resonant position of the resonant optical path is determined using the same method, thereby completing the cavity tuning. Since only one spherical mirror is adjusted at a time, the direction of the light beam is easily controlled, and the optimal beam path is uniquely determined. This avoids the difficulty in tuning caused by the uncertainty of the optimal path resulting from the simultaneous adjustment of two spherical mirrors. This is a new, efficient and accurate cavity tuning method, which is of great significance for optimizing laser gyro performance and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to make the present invention more easily understood, the present invention will be described in more detail with reference to the specific embodiments shown in the accompanying drawings. These drawings only depict typical embodiments of the present invention and should not be considered as limiting the scope of protection of the present invention.
[0019] Figure 1 This is a schematic structural diagram of the laser gyro active cavity tuning device according to an embodiment of the present utility model.
[0020] Figure 2 The diagram is a schematic diagram of the optical path formation in the first step of active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0021] Figure 3 The figure is a schematic diagram of the optical path formation in the second step of active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0022] Figure 4 This is a schematic diagram of the optical path formation in the third step of active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0023] Figure 5 This is a schematic diagram of light path formation in the fourth step of active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0024] Figure 6 This is a schematic diagram of light path formation in the fifth step of active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0025] Figure 7 This is a schematic diagram of light path formation in the sixth step of active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0026] Figure 8 This is a schematic diagram of the optical path formation in the seventh step of performing active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0027] Figure 9 This is a schematic diagram of light path formation in the eighth step of active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0028] Figure 10 This is a schematic diagram of the optical path formation in the ninth step of performing active cavity tuning of a laser gyroscope using the device of an embodiment of the utility model.
[0029] Reference numerals:
[0030] 10. Cavity to be adjusted; 11. First plane mirror; 12. Second plane mirror; 20. First gain laser tube; 30. Second gain laser tube; 40. First reflector; 41. Second reflector; 42. Fourth reflector; 43. Third reflector; 13. Third plane mirror; 14. Fourth plane mirror; 16. First spherical mirror; 17. Second spherical mirror; 70. Photodetector; 80. Collimating laser; 81. First aperture; 82. Second aperture; 83. Third aperture. DETAILED DESCRIPTION
[0031] The following describes the implementation methods of the present invention with reference to the accompanying drawings so that those skilled in the art can better understand the present invention and implement it. However, the enumerated embodiments are not intended to limit the present invention. Unless there is a conflict, the following embodiments and the technical features in the embodiments can be combined with each other, and the same components are represented by the same figure marks.
[0032] like Figure 1 As shown, the laser gyro active cavity tuning device of this embodiment includes:
[0033] The first gain laser tube 20, the second gain laser tube 30, the photodetector 70, the first reflecting mirror 40, the second reflecting mirror 41, the third reflecting mirror 43 and the fourth reflecting mirror 42,
[0034] The first gain laser tube 20 is placed on the left side of the cavity to be adjusted, and corresponds to the upper left corner of the cavity to be adjusted. The first reflector 40 is placed on the left side of the first gain laser tube 20. The second gain laser tube 30 is placed on the left side of the cavity to be adjusted, and corresponds to the lower left corner of the cavity to be adjusted. The second reflector 41 is placed on the left side of the second gain laser tube 30. The photodetector 70 is placed below the cavity to be adjusted, and corresponds to the lower right corner of the cavity to be adjusted. The third reflector 43 is placed below the cavity to be adjusted, and corresponds to the lower left corner of the cavity to be adjusted. The fourth reflector 42 is placed above the cavity to be adjusted, and corresponds to the upper left corner of the cavity to be adjusted.
[0035] In this embodiment, a collimating laser 80, a first aperture 81, a second aperture 82 and a third aperture 83 are also included.
[0036] The collimating laser 80 is placed on the right side of the cavity to be adjusted, and corresponds to the lower right corner of the cavity to be adjusted 10. The first aperture 81 is set between the cavity to be adjusted 10 and the collimating laser 80. The second aperture 82 is placed between the first gain laser tube 20 and the cavity to be adjusted 10. The third aperture 83 is placed between the second gain laser tube 30 and the cavity to be adjusted 10.
[0037] In this embodiment, the first reflector 40 is a plane reflector, the second reflector 41 is a curved reflector, the third reflector 43 is a plane reflector, and the fourth reflector 42 is a curved reflector.
[0038] In other embodiments, the first reflector 40 may be a curved reflector, the second reflector 41 may be a plane reflector, the third reflector 43 may be a curved reflector, and the fourth reflector 42 may be a plane reflector.
[0039] In this embodiment, one of the first gain laser tube 20 and the second gain laser tube 30 is a gain laser tube with a Brewster window, and the other is a gain laser tube with an anti-reflection film.
[0040] A dual gain tube structure is adopted, one of which adopts a Brewster window structure and the other adopts an anti-reflection film lens gain tube structure, which can effectively avoid the gain degradation problem caused by polarization matching problems.
[0041] Specifically, one purpose of using a Brewster window laser tube is to ensure laser polarization and improve beam quality. When unpolarized light is incident at the Brewster angle, the reflected portion becomes completely S-polarized light, while the transmitted portion becomes partially P-polarized light. Multiple passes of the light beam through the Brewster window significantly reduce the S component in the transmitted beam, thereby improving the purity and quality of the P-polarized light.
[0042] Another reason why the laser gain tube uses an anti-reflection film flat sheet packaging structure is that if two Brewster window laser tubes are used, the two laser tubes will inevitably have an angular error in the direction perpendicular to the optical axis during installation, resulting in inconsistent directions of transmitted polarized light, forming a competitive relationship and causing power reduction. Therefore, this laser tube adopts a non-Brewster window structure, but instead uses a surface anti-reflection film flat sheet packaging, which can allow polarized light in all directions to pass through with low loss and ensure laser power.
[0043] The process of implementing active cavity tuning of a laser gyroscope using the device of this embodiment is as follows:
[0044] Before cavity tuning, a first plane mirror 11 is installed at the upper right corner of the cavity 10 to be tuned of the laser gyroscope, and a second plane mirror 12 is installed at the lower right corner of the cavity to be tuned.
[0045] Step 1: Coarse adjustment of the positions of the first gain laser tube 20 and the second gain laser tube 30
[0046] like Figure 2 As shown, the collimating laser 80 is turned on, the photodetector 70 is turned off, and the positions of the second gain laser tube 30 and the second reflector 41 are adjusted so that the centers of the incident light spot and the reflected light spot passing through the third aperture 83 coincide with the center of the third aperture 83; the positions of the first gain laser tube 20 and the first reflector 40 are adjusted so that the centers of the incident light spot and the reflected light spot passing through the second aperture 82 coincide with the center of the second aperture 82; the collimating laser 80 is turned off, and the second aperture 82 and the third aperture 83 are removed.
[0047] Specifically, after adjusting the collimation of the collimating laser 80 in this step, the collimated light emitted from the collimating laser passes through the second plane mirror 12 and the second gain laser tube 30, is reflected by the curved second reflector 41, is reflected by the second plane mirror 12 and the first plane mirror 11, enters the first gain laser tube 20, and is reflected by the flat first reflector 40. The third aperture 83 is used to observe whether the incident and reflected light spots of the optical path 81-10-83-30-41-30-83 overlap. If not, the positions of the second gain laser tube 30 and the second reflector 41 are roughly adjusted so that the incident and reflected light spots passing through the third aperture 83 overlap, thereby achieving coaxial optical path coaxiality. In other words, the second gain laser tube 30 is substantially coaxial with the lower section of the cavity 10 to be adjusted. Then observe through the second aperture 82 whether the incident and reflected light spots of the optical path 81-10-83-30-41-30-83-12-11-10-82-20-40-20-82 coincide with each other. If not, roughly adjust the positions of the first gain laser tube 20 and the first reflector 40 so that the incident light spot and the reflected light spot passing through the second aperture 82 coincide with each other, thereby realizing the above-mentioned coaxial optical path, that is, the first gain laser tube 20 is basically coaxial with the upper section of the cavity 10 to be adjusted.
[0048] Step 2: Fine-tune the positions of the first gain laser tube 20 and the second gain laser tube 30
[0049] like Figure 3 As shown, the first gain laser tube 20, the second gain laser tube 30 and the photodetector 70 are turned on, and the positions of the first gain laser tube 20 and the second gain laser tube 30 are adjusted so that the optical power detected by the photodetector 70 is maximized, and the positions of the first gain laser tube 20 and the second gain laser tube 30 are fixed.
[0050] Specifically, in this step, the first gain laser tube 20 and the second gain laser tube 30 are turned on, and the lasers emitted by the first gain laser tube 20 and the second gain laser tube 30 and the resonant gain function of the two are used to form a resonant optical path 41-30-10-20-40. The transmitted light emitted from the second plane mirror 12 is collected by the photodetector 70, and the first gain laser tube 20 and the second gain laser tube 30, as well as the first reflector 40 and the second reflector 41, are fine-tuned to maximize the optical power detected by the photodetector 70, that is, to maximize the optical power of the resonant cavity 41-30-10-20-40, that is, the optical path is precisely coaxial and the power is optimal, thereby achieving precise coaxiality between the second gain laser tube 30 and the lower section of the cavity 10 to be adjusted, and precise coaxiality between the first gain laser tube 20 and the upper section of the cavity 10 to be adjusted.
[0051] Step 3: Coarse adjustment of the position of the third reflector 43
[0052] like Figure 4 As shown, a third plane mirror 13 is installed at the upper left corner of the cavity 10 to be adjusted of the laser gyroscope;
[0053] A third aperture 83 is set between the second gain laser tube 30 and the cavity 10 to be adjusted, the collimating laser 80 is turned on and the photodetector 70 is turned off, and the position of the third reflector 43 is adjusted so that the centers of the incident light spot and the reflected light spot passing through the third aperture 83 coincide with the center of the third aperture 83; the collimating laser 80 is turned off, and the third aperture 83 is removed.
[0054] Specifically, this step utilizes the collimated light emitted by the collimated laser to form an optical path 81-12-10-83-30-41-30-83-12-11-13-43-13-11-12-83, and observes whether the incident and reflected light spots of the above optical path coincide through the third aperture 83. If they do not coincide, the orientation of the third reflector 43 is roughly adjusted so that the incident light spot and the reflected light spot passing through the third aperture 83 coincide and are both in the center of the aperture, thereby achieving that the laser light incident on the mirror surface of the third reflector 43 is roughly perpendicular to its mirror surface, and the coaxial adjustment is completed.
[0055] Step 4: Fine-tune the position of the third reflector 43
[0056] like Figure 5 As shown, the first gain laser tube 20 is turned off, the second gain laser tube 30 and the photodetector 70 are turned on, the position of the third reflector 43 is adjusted so that the optical power detected by the photodetector 70 is maximum, and the position of the third reflector 43 is fixed.
[0057] Specifically, this step utilizes the laser emitted by the second gain laser tube 30 and its resonant gain function to form an active cavity 41-30-10-43, and fine-tune the orientation of the third reflector 43 so that the optical power of the resonant cavity 41-30-10-43 is maximized (i.e., the optical power detected by the photodetector 70 is maximized), thereby achieving that the laser incident on the mirror surface of the third reflector 43 is precisely perpendicular to its mirror surface.
[0058] Step 5: Coarse adjustment of the position of the fourth reflector 42
[0059] like Figure 6 As shown, the third plane mirror 13 is removed from the cavity 10 to be adjusted, and the fourth plane mirror 14 is installed at the lower left corner of the cavity 10 to be adjusted of the laser gyroscope;
[0060] A second aperture 82 is set between the first gain laser tube 20 and the cavity to be adjusted 10, the collimating laser 80 is turned on and the photodetector 70 is turned off, and the position of the fourth reflector 42 is adjusted so that the centers of the incident light spot and the reflected light spot passing through the second aperture 82 coincide with the center of the second aperture 82; the collimating laser 80 is turned off and the second aperture 82 is removed.
[0061] Specifically, this step uses the collimated light emitted by the collimated laser to form the optical path 12-14-42-14-12-11-82-20-40-20-82, and coarsely adjusts the orientation of the fourth reflector 42 so that the incident light spot and the reflected light spot passing through the second aperture 82 coincide and are at the center of the second aperture 82, thereby achieving that the laser light incident on the mirror surface of the fourth reflector 42 is roughly perpendicular to its incident point tangent, completing the coaxial coarse adjustment.
[0062] Step 6: Fine-tune the position of the fourth reflector 42
[0063] like Figure 7 As shown, the first gain laser tube 20 and the photodetector 70 are turned on, the second gain laser tube 30 is turned off, the position of the fourth reflector 42 is adjusted so that the optical power detected by the photodetector 70 is maximized, and the position of the fourth reflector 42 is fixed.
[0064] Specifically, this step utilizes the laser emitted by the first gain laser tube 20 and its resonant gain function, and the resonant cavity composed of 40-20-10-42 generates laser through resonance, and fine-tunes the orientation of the fourth reflector 42 so that the optical power of the resonant cavity 40-20-10-42 is maximized (that is, the optical power detected by the photodetector 70 is maximized), thereby achieving the precise perpendicularity of the laser incident on the mirror surface of the fourth reflector 42 to complete the coaxial fine-tuning.
[0065] Step 7: Determine the position of the first spherical mirror 16
[0066] like Figure 8As shown, the first plane mirror 11 is removed from the cavity to be adjusted, and the first spherical mirror 16 is installed at the upper right corner of the cavity to be adjusted of the laser gyroscope; the first gain laser tube 20 and the photodetector 70 are turned on, the second gain laser tube 30 is turned off, and the position of the first spherical mirror 16 is adjusted so that the light power detected by the photodetector 70 is the maximum, and the position of the first spherical mirror 16 is fixed.
[0067] Specifically, in this step, the first plane mirror 11 is replaced by the first spherical mirror 16. The laser emitted by the first gain laser tube 20 and its resonance gain function are used, and the resonant cavity composed of 40-20-10-42 generates laser through resonance, and the orientation of the first spherical mirror 16 is fine-tuned so that the optical power of the resonant cavity 40-20-10-42 is maximized (that is, the optical power detected by the photodetector 70 is maximized), thereby realizing the adjustment of the first spherical mirror 16.
[0068] Step 8: Determine the position of the second spherical mirror 17
[0069] like Figure 9 As shown, the fourth plane mirror 14 is removed from the cavity to be adjusted, and the second spherical mirror 17 is installed at the upper left corner of the cavity to be adjusted of the laser gyroscope; the second gain laser tube 30 and the photodetector 70 are turned on, the first gain laser tube 20 is turned off, and the position of the second spherical mirror 17 is adjusted so that the optical power detected by the photodetector 70 is maximized, and the position of the second spherical mirror 17 is fixed;
[0070] Specifically, in this step, the fourth plane mirror 14 is replaced by the second spherical mirror 17. The laser emitted by the second gain laser tube 30 and its resonance gain function are used to generate laser through resonance in the resonant cavity composed of 41-30-10-43. The orientation of the second spherical mirror 17 is fine-tuned so that the optical power of the resonant cavity 41-30-10-43 is maximized (that is, the optical power detected by the photodetector 70 is maximized), thereby realizing the adjustment of the second spherical mirror 17.
[0071] Step 9: Install the fourth plane mirror 14
[0072] like Figure 10 As shown, a fourth plane mirror 14 is installed at the lower left corner of the cavity to be adjusted of the laser gyroscope to complete the cavity adjustment of the laser gyroscope.
[0073] The embodiments described above are merely preferred embodiments of the present invention. The phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments" used in this specification may refer to one or more of the same or different embodiments of the present disclosure. Any common changes and substitutions made by those skilled in the art within the scope of the present invention are intended to be encompassed within the scope of protection of the present invention.
Claims
1. A laser gyro active cavity tuning device, comprising: a first gain laser tube (20), a second gain laser tube (30), a photodetector (70), a first reflecting mirror (40), a second reflecting mirror (41), a third reflecting mirror (43) and a fourth reflecting mirror (42), The first gain laser tube (20) is placed on the left side of the cavity to be adjusted and corresponds to the upper left corner of the cavity to be adjusted; the first reflector (40) is placed on the left side of the first gain laser tube (20); the second gain laser tube (30) is placed on the left side of the cavity to be adjusted and corresponds to the lower left corner of the cavity to be adjusted; the second reflector (41) is placed on the left side of the second gain laser tube (30); the photodetector (70) is placed below the cavity to be adjusted and corresponds to the lower right corner of the cavity to be adjusted; the third reflector (43) is placed below the cavity to be adjusted and corresponds to the lower left corner of the cavity to be adjusted; and the fourth reflector (42) is placed above the cavity to be adjusted and corresponds to the upper left corner of the cavity to be adjusted.
2. The laser gyro active cavity tuning device according to claim 1, characterized in that: It also includes a collimating laser (80), a second aperture (82) and a third aperture (83), The collimating laser (80) is placed on the right side of the cavity to be adjusted and corresponds to the lower right corner of the cavity to be adjusted (10). The second aperture (82) is placed between the first gain laser tube (20) and the cavity to be adjusted (10). The third aperture (83) is placed between the second gain laser tube (30) and the cavity to be adjusted (10).
3. The laser gyro active cavity tuning device according to claim 2, characterized in that: Also includes: A first diaphragm (81) is provided between the cavity to be adjusted (10) and the collimating laser (80).
4. The laser gyro active cavity tuning device according to any one of claims 1 to 3, characterized in that: The first reflector (40) is a plane reflector, the second reflector (41) is a curved reflector, the third reflector (43) is a plane reflector, and the fourth reflector (42) is a curved reflector.
5. The laser gyro active cavity tuning device according to any one of claims 1 to 3, characterized in that: The first reflector (40) is a curved reflector, the second reflector (41) is a plane reflector, the third reflector (43) is a curved reflector, and the fourth reflector (42) is a plane reflector.
6. The laser gyro active cavity tuning device according to any one of claims 1 to 3, characterized in that: One of the first gain laser tube (20) and the second gain laser tube (30) is a gain laser tube with a Brewster window.
7. The laser gyro active cavity tuning device according to claim 6, characterized in that: The other of the first gain laser tube (20) and the second gain laser tube (30) is a gain laser tube with an anti-reflection film.