Angle-adjustable frequency stabilizing device for laser gyroscope

Abstract

The invention discloses an angle-adjustable frequency stabilization device for a laser gyroscope, and belongs to the field of laser gyroscopes. The device comprises a frequency stabilization spherical mirror and an annular thin rib structure formed by processing a glass material, coaxial columnar protrusions are arranged at the two ends of the center of the frequency stabilization spherical mirror, the end of the columnar protrusion at one end is a concave spherical surface, and the columnar protrusion at the other end is a jackscrew contact surface; the clamping mechanism is used for installing the frequency stabilization spherical mirror; the 3-4 jackscrews are connected with the grabbing and clamping mechanism through threads, and the end surfaces of the jackscrews are in tight contact with the jackscrew contact surfaces on the columnar bulges of the frequency stabilization spherical mirror; the two piezoelectric ceramic pieces are arranged on the upper surface and the lower surface of the card grabbing mechanism respectively and used for achieving frequency stabilization through voltage control. According to the invention, through different screw-in amounts of 3-4 jackscrews, the reflection angle of the frequency stabilization spherical mirror can be accurately adjusted, the angle processing error of a laser gyroscope cavity is made up, and the problem that a new angle error may be introduced due to the fact that the angle of an existing clamping type frequency stabilization control mirror cannot be adjusted is solved.

Description

Technical Field

[0001] This invention relates to the field of laser gyroscopes, and more specifically, to an angle-adjustable frequency stabilization device for laser gyroscopes. Background Technology

[0002] As an advanced photoelectric inertial sensing instrument, the laser gyroscope eliminates the need for the high-speed rotor required by electromechanical gyroscopes, offering significant performance advantages. It is an ideal angular velocity sensor for a new generation of highly sensitive, high-precision, and wide dynamic range strapdown inertial systems, and is widely used in attitude measurement, positioning, and orientation systems in the sea, land, air, and space.

[0003] The working principle of a laser gyroscope is the Sagnac effect. When there is angular motion relative to inertial space, two beams of light moving in opposite directions within a ring laser will produce an optical path difference, which causes frequency splitting and generates a frequency difference. The magnitude of the frequency difference is proportional to the angular velocity. The angular velocity can be measured by measuring the frequency difference between the two beams.

[0004] The ring laser is the core component of a laser gyroscope. Its closed optical path is typically formed by 3-4 mirrors, which are fixed to the corresponding mounting surfaces of the ring laser cavity using optical adhesive. Optical adhesive, achieved through precision polishing, gives the contact surfaces of the components a high degree of roughness. The components are bonded together by molecular attraction. Optical adhesive offers advantages such as strong adhesion, no pollution, and good sealing, making it a common technology in laser gyroscope manufacturing. However, it also has the disadvantage of not being able to adjust the angles between the components, thus placing high demands on the angular machining accuracy of the cavity. Existing gripper-type frequency stabilization control mirrors offer good stability and are widely used in the frequency stabilization control of laser gyroscopes. However, these gripper-type cavity length control mirrors may have inherent defects, deviations in the force and application point of the frequency stabilization control elements, and lack angle adjustment capabilities. This not only fails to compensate for angular machining errors in the cavity but may also introduce new angular errors, leading to closed optical path distortion, reduced cavity tuning yield, and impacting the performance of the laser gyroscope. Therefore, we propose an angle-adjustable frequency stabilization device for laser gyroscopes. Summary of the Invention

[0005] The purpose of this invention is to provide an angle-adjustable frequency stabilization device for a laser gyroscope, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An angle-adjustable frequency stabilization device for a laser gyroscope includes: The frequency-stabilized spherical mirror is made of glass material with a ring-shaped thin rib structure. Both ends of the center of the frequency-stabilized spherical mirror are provided with coaxial columnar protrusions. One end of the columnar protrusion is a concave spherical surface with a high reflectivity film coated on it. The other end of the columnar protrusion is the top screw contact surface. The card-grabbing mechanism is used to install the frequency-stabilized spherical lens; Three to four set screws are connected to the clamping mechanism via threads. Their end faces are in close contact with the set screw contact surfaces on the columnar protrusions of the frequency-stabilized spherical mirror. The reflection angle of the frequency-stabilized spherical mirror can be adjusted by different screw advance amounts. Two piezoelectric ceramic plates are respectively set on the upper and lower surfaces of the gripping mechanism to achieve frequency stabilization through voltage control.

[0007] Preferably, the radius of curvature of the concave spherical surface of the frequency-stabilized spherical mirror is 0.5m to 10m.

[0008] Preferably, eight grippers are evenly arranged around the gripping mechanism. The gripping mechanism is fixed to the frequency-stabilized spherical mirror by the grippers. A protruding structure is provided on the inner side of the end of the gripper, and the protruding structure contacts the outer wall of the frequency-stabilized spherical mirror.

[0009] Preferably, the set screws are arranged coaxially and evenly with the outer edge near the center of the gripping mechanism, with two set screws arranged on the optical path plane and the remaining set screws arranged on a plane perpendicular to the optical path plane.

[0010] Preferably, the piezoelectric ceramic sheet is bonded to the upper and lower surfaces of the gripping mechanism by adhesive or solder.

[0011] Preferably, a circular hole is provided on the piezoelectric ceramic sheet at the position corresponding to the set screw.

[0012] Preferably, the threaded connection between the set screw and the clamping mechanism is coated with epoxy adhesive to fix the position of the set screw.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention retains the frequency stabilization capability of traditional gripper-type frequency stabilization devices and adds an angle adjustment function. By adjusting the different advance amounts of 3 to 4 set screws, the reflection angle of the frequency stabilization spherical mirror can be precisely adjusted to compensate for the angle processing error of the laser gyroscope cavity, thus solving the problem that existing gripper-type frequency stabilization control mirrors cannot adjust the angle and may introduce new angle errors. The adjustable angle characteristic reduces the angle processing accuracy requirements of the mounting surface of the frequency stabilization mirror, reduces product scrap due to insufficient processing accuracy, and thus reduces production difficulty and cost.

[0014] (2) The present invention reduces optical path distortion by adjusting the angle, and the piezoelectric ceramic sheet can dynamically compensate for the optical path change caused by the change of ambient temperature through voltage control, maintain optical path stability, reduce laser loss, keep the optical path in an ideal state, and improve the accuracy and performance of the laser gyroscope.

[0015] (3) The annular thin rib structure and coaxial columnar protrusion design of the frequency-stabilized spherical mirror of the present invention ensure optical performance and adjustment stability; the eight claws and protrusion structure of the gripping mechanism enhance the fixing firmness and reduce stress deformation; the epoxy glue fixing at the top screw thread and the reliable connection method of the piezoelectric ceramic sheet ensure that the device is not prone to positional displacement during long-term operation, thereby improving the overall stability and service life.

[0016] (4) This invention effectively solves problems such as closed optical path distortion by adjusting the angle and optimizing the optical path, significantly improves the yield of laser gyroscope cavity adjustment process and improves production efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a reverse view of the overall structure of the present invention; Figure 3 This is a cross-sectional schematic diagram of the present invention; Figure 4 This is an exploded view of the present invention.

[0018] The labels in the diagram are as follows: 1. Frequency-stabilized spherical mirror; 2. Card gripping mechanism; 3. Piezoelectric ceramic sheet; 4. Set screw. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Example: Please see Figure 1-4 An angle-adjustable frequency stabilization device for a laser gyroscope, comprising: The frequency-stabilized spherical mirror 1 is made of glass with a ring-shaped thin rib structure, which ensures lightweight structure to reduce interference with optical path stability, while maintaining good optical performance through material properties. Both ends of the frequency-stabilized spherical mirror 1 have coaxial cylindrical protrusions. One end of the cylindrical protrusion is a concave spherical surface coated with a high-reflectivity film, which can efficiently reflect laser light to ensure optical path closure accuracy. The radius of curvature of the concave spherical surface of the frequency-stabilized spherical mirror 1 is 0.5m to 10m. The other end of the cylindrical protrusion is the top wire contact surface, providing a stable fulcrum for angle adjustment, enabling precise control of the reflection angle. Simultaneously, the specific curvature range of the concave spherical surface adapts to the optical path design requirements of the laser gyroscope, reducing light loss.

[0021] The gripping mechanism 2 is used to install the frequency-stabilized spherical mirror 1. The gripping mechanism 2 has eight grippers evenly arranged around its perimeter. The gripping mechanism 2 is fixed to the frequency-stabilized spherical mirror 1 by the grippers. The inner side of the gripper end has a protruding structure that contacts the outer wall of the frequency-stabilized spherical mirror 1. This not only enhances the stability of the fixation and prevents displacement or shaking of the frequency-stabilized spherical mirror 1 during operation, but also reduces local stress on the frequency-stabilized spherical mirror 1 through multi-point uniform contact, preventing deformation caused by uneven force and affecting the optical path accuracy. The evenly distributed gripper design also ensures the force balance of the frequency-stabilized spherical mirror 1, further improving the overall stability of the device.

[0022] Three to four set screws 4 are connected to the clamping mechanism 2 via threads. Their end faces are in close contact with the set screw contact surfaces on the columnar protrusions of the frequency-stabilized spherical mirror 1. The reflection angle of the frequency-stabilized spherical mirror 1 can be adjusted by different screw advances of different set screws 4, thereby compensating for cavity angle processing errors and reducing optical path distortion. The threaded connection between the set screws 4 and the clamping mechanism 2 is coated with epoxy resin to fix the position of the set screws 4. It can be locked after the angle adjustment is completed to avoid angle deviation caused by vibration and other factors, ensuring the long-term stability of the adjustment effect. Moreover, the distribution design of the set screws 4 in the optical path plane and vertical plane can realize multi-dimensional angle adjustment and improve the comprehensiveness of optical path optimization.

[0023] Two piezoelectric ceramic plates 3 are respectively disposed on the upper and lower surfaces of the gripping mechanism 2. They are used to achieve frequency stabilization through voltage control. Voltage control allows for dynamic adjustment of the optical path length, effectively compensating for optical path fluctuations caused by factors such as ambient temperature changes, and maintaining stable laser frequency. Circular holes are provided on the piezoelectric ceramic plates 3 corresponding to the positions of the set screws 4. These holes avoid structural interference with the set screws, ensuring that set screw adjustment and piezoelectric ceramic plate operation do not affect each other. The piezoelectric ceramic plates 3 are bonded to the upper and lower surfaces of the gripping mechanism 2 by adhesive bonding or soldering. This method of fixing ensures a strong connection and adapts to different installation requirements under various working conditions, improving the device's adaptability.

[0024] In this application, the set screws 4 are evenly arranged coaxially with the outer edge near the center of the gripping mechanism 2. Two set screws 4 are arranged on the optical path plane, and the remaining set screws 4 are arranged on a plane perpendicular to the optical path plane. The distribution design of the set screws 4 on the optical path plane and the perpendicular plane can realize multi-dimensional angle adjustment and improve the comprehensiveness of optical path optimization. The upper end of the set screw 4 has a groove for fitting with a special tool, so that the operator can apply torque to the set screw 4 and change its screw advance by rotating the set screw 4, thereby precisely adjusting the reflection angle of the frequency-stabilized spherical mirror 1.

[0025] The frequency stabilization device provided by this invention, in addition to possessing all the functions and advantages of traditional frequency stabilization devices, also has angle adjustment capability. This reduces the angle processing requirements of the mounting surface of the frequency stabilizing mirror, decreases optical path distortion, and improves the yield of cavity tuning and the performance of the laser gyroscope. By controlling the different advance amounts of different set screws 4, the angle between the central convex post of the frequency stabilizing spherical mirror 1 and the optical path can be controlled, ensuring the optical path is within the ideal range, reducing laser loss, and improving the accuracy of the laser gyroscope. After the angle adjustment is completed, epoxy adhesive is applied to the threads of the set screws to fix their position. The circular piezoelectric ceramic sheet 3 has four circular holes designed at corresponding positions of each set screw 4. It is bonded to the upper and lower surfaces of the gripping mechanism with adhesive (or soldered to the upper and lower surfaces). During normal operation, different voltages are applied to the piezoelectric ceramic sheet 3, causing the four set screws 4 to advance and retreat synchronously. This can change the optical path of the laser, compensate for changes in optical path caused by changes in ambient temperature, maintain optical path stability, and thus maintain the stability of the laser frequency.

[0026] In specific operation, a photodetector is used to measure the output light intensity of the laser. After power-on, an initial voltage U0 is applied to the piezoelectric ceramic plate through the control circuit. The light intensity measured by the photodetector at this time is recorded as I0. Then, the voltage applied to the piezoelectric ceramic plate is adjusted to U0 + ΔU through the control circuit, and the light intensity measured by the photodetector at this time is recorded as I1. If I1 ≥ I0, the voltage applied to the piezoelectric ceramic plate is further adjusted to U0 + 2ΔU. If I1 < I0, the voltage applied to the piezoelectric ceramic plate is adjusted to U0. And so on. Let the current voltage applied to the piezoelectric ceramic be U', the current measured light intensity be I', the voltage applied to the piezoelectric ceramic at the previous moment be U, and the light intensity at the previous moment be I. Then the control logic is: If I'-I≥0, then adjust the voltage to 2U'-U; If I'-I < 0, then adjust the voltage to U; The above control process is automatically and rapidly executed iteratively by the control chip in the control circuit: by monitoring the light intensity signal fed back by the photodetector in real time, the voltage applied to the piezoelectric ceramic sheet is dynamically adjusted, and finally the laser output light intensity is stabilized at the center peak of the resonant mode (i.e., the light intensity maximum state), thereby ensuring the long-term stability of the laser's operating frequency.

[0027] Once the piezoelectric ceramic plate has stabilized the light intensity at its maximum value at the current angle, the angle between the frequency-stabilizing spherical mirror and the optical path is changed by adjusting the advance of the four set screws in stages: after adjusting each set screw 4, the trend of light intensity change is observed until the angle reaches the ideal position—at which point the laser optical path closure accuracy is the highest, energy loss is the lowest, and the light intensity measured by the photodetector reaches the global maximum value (i.e., the optimal light intensity state of the entire system). In this state, epoxy adhesive is applied to the threaded connection between the set screw 4 and the gripping mechanism 2. After the adhesive layer cures, the position of the set screw 4 is permanently locked, and the angle adjustment process of the entire frequency stabilization device is completed.

[0028] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An angle-adjustable frequency stabilization device for a laser gyroscope, characterized in that, include: The frequency-stabilized spherical mirror (1) is made of glass material and has a ring-shaped thin rib structure. Both ends of the frequency-stabilized spherical mirror (1) are provided with coaxial columnar protrusions. One end of the columnar protrusion is a concave spherical surface, and a high reflectivity film is coated on the concave spherical surface. The other end of the columnar protrusion is a top wire contact surface. The card-grabbing mechanism (2) is used to install the frequency-stabilized spherical mirror (1); Three to four set screws (4) are connected to the gripping mechanism (2) by threads. Their end faces are in close contact with the set screw contact surface on the columnar protrusion of the frequency-stabilized spherical mirror (1). The reflection angle of the frequency-stabilized spherical mirror (1) can be adjusted by different screw advance amounts of different set screws (4). Two piezoelectric ceramic plates (3) are respectively disposed on the upper and lower surfaces of the gripping mechanism (2) for frequency stabilization through voltage control.

2. The angle-adjustable frequency stabilization device for a laser gyroscope according to claim 1, characterized in that: The radius of curvature of the concave spherical surface of the frequency-stabilized spherical mirror (1) is 0.5m to 10m.

3. The angle-adjustable frequency stabilization device for a laser gyroscope according to claim 1, characterized in that: The gripping mechanism (2) is evenly arranged with eight gripping claws around it. The gripping mechanism (2) is fixed to the frequency-stabilized spherical mirror (1) by the gripping claws. The inner side of the end of the gripping claw is provided with a protruding structure, and the protruding structure is in contact with the outer wall of the frequency-stabilized spherical mirror (1).

4. The angle-adjustable frequency stabilization device for a laser gyroscope according to claim 1, characterized in that: The set screws (4) are arranged coaxially and evenly on the outer edge near the center of the gripping mechanism (2), with two set screws (4) arranged on the optical path plane and the remaining set screws (4) arranged on a plane perpendicular to the optical path plane.

5. The angle-adjustable frequency stabilization device for a laser gyroscope according to claim 1, characterized in that: The piezoelectric ceramic sheet (3) is bonded to the upper and lower surfaces of the gripping mechanism (2) by adhesive or solder.

6. The angle-adjustable frequency stabilization device for a laser gyroscope according to claim 1, characterized in that: A circular hole is provided on the piezoelectric ceramic sheet (3) at the position corresponding to the set screw (4).

7. The angle-adjustable frequency stabilization device for a laser gyroscope according to claim 1, characterized in that: The threaded connection between the set screw (4) and the gripping mechanism (2) is coated with epoxy resin to fix the position of the set screw (4).

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