Laser gyroscope light combination prism with groove

Abstract

The utility model discloses a laser gyroscope light combination prism with a groove, which belongs to the field of laser gyroscopes and comprises a light combination prism which is optically cemented on a reflecting mirror of an annular resonant cavity of a laser gyroscope through an optical cement surface and is used for carrying out light combination interference on two laser beams propagating clockwise and anticlockwise in the annular resonant cavity of the laser gyroscope; a groove is formed in a laser passing position on the optical cement surface, and a semi-transparent and semi-reflective film is plated in the groove and is used for reducing the loss of a laser beam; the depth of the groove is greater than or equal to the thickness of the semi-transparent and semi-reflective film; the diameter or the width of the groove is larger than the diameter or the width of the semi-transparent and semi-reflective film, and the semi-transparent and semi-reflective film is plated at the central position of the groove. And the photoelectrode tube is adhered to the emergent end surface of the light combination prism and is used for detecting interference signals generated by two laser beams which are propagated clockwise and anticlockwise in the annular resonant cavity of the laser gyroscope.

Description

Technical Field

[0001] This utility model belongs to the field of laser gyroscope technology, and in particular relates to a laser gyroscope beam combining prism with a groove. Background Technology

[0002] Laser gyroscopes measure rotation by utilizing the frequency difference between two laser beams propagating in opposite directions within a ring resonant cavity. A beam combiner prism is a key component in a laser gyroscope; it measures the angular displacement of an object by combining two laser beams traveling in opposite directions and detecting the amount of movement in the interference fringes. In other words, the beam combiner prism's main functions are beam combining and interference fringe detection. The performance of the beam combiner prism directly affects the measurement accuracy of the laser gyroscope and is also a significant factor influencing its overall performance. Under harsh conditions such as high and low temperatures and high vibration, the beam combiner prism needs to maintain sufficient stability and connection strength to ensure the laser gyroscope functions properly. The beam combining section is crucial to the laser gyroscope's signal readout system. The readout system typically consists of a beam combiner prism and a photodiode. To reduce laser beam loss as it passes through the beam combiner prism, a small area of ​​semi-transparent, semi-reflective film with a certain transmittance is generally deposited on the reflector surface between the beam combiner prism and the resonant cavity mirror at the point where the laser beam passes.

[0003] Because the photoresist surface contains a semi-transparent and semi-reflective film of a certain thickness, when the light-combining prism and the reflector are bonded, the photoresist, which is higher in the center and lower around the edges, will generate stress on the light-combining prism and the reflector. This also reduces the photoresist area, affecting the connection strength and reliability, and consequently adversely affecting the performance of the laser gyroscope, even leading to photoresist detachment and failure. To reduce photoresist stress, patents CN 110986910 A and CN 110986911A employ the method of depositing four auxiliary films and a forked auxiliary film, placing the light-transmitting surface and the photoresist surface at the same height, thus reducing photoresist stress. However, this significantly reduces the photoresist area and the photoresist interface strength, adversely affecting reliability and performance under harsh conditions such as high and low temperatures and high vibration. Utility Model Content

[0004] The technical problem solved by this utility model: This utility model provides a laser gyroscope beam combining prism with a groove to solve the problems mentioned in the background art.

[0005] The technical solution of this utility model: a laser gyroscope beam combining prism with a groove, comprising:

[0006] The optical combining prism (30) is bonded to the reflector (20) of the laser gyroscope ring resonator (10) by optical adhesive;

[0007] The optical adhesive surface of the optical combining prism (30) has a groove, and a semi-transparent and semi-reflective film is coated in the groove.

[0008] Furthermore,

[0009] The groove is located where the laser passes through, and the groove can be circular, square, or U-shaped.

[0010] Furthermore,

[0011] The surface roughness (RMS) of the bottom surface of the groove is no greater than 5 nm, and the flatness of the bottom surface of the groove is no greater than 60 nm.

[0012] Furthermore,

[0013] The groove depth is greater than or equal to the thickness of the semi-permeable and semi-reflective film layer.

[0014] Furthermore,

[0015] The diameter or width of the groove is greater than the diameter or width of the semi-permeable and semi-reflective membrane.

[0016] Furthermore,

[0017] The semi-transparent and semi-reflective film is deposited at the center of the groove.

[0018] This invention includes a beam-combining prism mounted on a reflector of a laser gyroscope's ring resonant cavity using an optical adhesive. This prism is used to combine and interfere two clockwise and counterclockwise propagating laser beams within the ring resonant cavity. The optical adhesive surface has a groove at the laser passage point, and a semi-transparent, semi-reflective film is deposited within the groove to reduce laser beam loss. The depth of the groove is greater than or equal to the thickness of the semi-transparent, semi-reflective film. The diameter or width of the groove should be greater than the diameter or width of the semi-transparent, semi-reflective film, which is deposited at the center of the groove. An optical electrode tube bonded to the exit end face of the beam-combining prism is used to detect the interference signal generated by the two clockwise and counterclockwise propagating laser beams within the ring resonant cavity. This method achieves the goals of increasing the optical adhesive area, enhancing the interfacial affinity between similar materials, reducing optical adhesive stress, and improving the reliability of the beam-combining prism and the gyroscope performance under harsh operating conditions. Attached Figure Description

[0019] Figure 1 The diagram shows the structure of the beam combining prism in a laser gyroscope;

[0020] Figure 2 This utility model relates to a schematic diagram of the bonding end face of the light-combining prism in the light-combining device.

[0021] The above figures include the following reference numerals:

[0022] 10. Laser gyroscope cavity; 20. Reflector; 30. Optical combining prism; 31. Optical adhesive surface; 32. Groove; 33. Semi-transparent and semi-reflective film; 40. Phototube. Detailed Implementation

[0023] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings.

[0024] This utility model embodiment provides a grooved laser gyroscope beam combining prism, including...

[0025] A beam combining prism 30, which is bonded to the reflector 20 of the laser gyroscope ring resonator 10 via an optical adhesive surface 31, is used to combine and interfere two laser beams that propagate clockwise and counterclockwise within the laser gyroscope ring resonator 10.

[0026] The photoresist surface 31 has a groove, and a semi-transparent and semi-reflective film is deposited in the groove to reduce the loss of the laser beam.

[0027] The phototube bonded to the exit end face of the beam combining prism is used to detect the interference signal generated by two laser beams propagating in clockwise and counterclockwise directions within the ring resonant cavity of the laser gyroscope.

[0028] The optical adhesive surface has grooves, and a semi-transparent, semi-reflective film is deposited inside the grooves to reduce laser beam loss. A photodiode bonded to the exit end face of the beam combining prism is used to detect the interference signal generated by two laser beams propagating in clockwise and counterclockwise directions within the ring resonant cavity of the laser gyroscope.

[0029] The groove is located where the laser passes through. The groove can be circular, square, U-shaped, or other shapes, and the surface roughness RMS of the bottom surface of the groove is no greater than 5nm.

[0030] The groove depth is greater than or equal to the thickness of the semi-permeable and semi-reflective film layer.

[0031] The diameter or width of the groove should be greater than the diameter or width of the semi-permeable and semi-reflective membrane.

[0032] The semi-transparent and semi-reflective film should be deposited at the center of the groove.

[0033] The light-combining prism is bonded to the reflector of the laser gyroscope's ring resonant cavity using an optical adhesive method.

[0034] like Figures 1 to 2 As shown, this utility model provides a laser gyroscope beam combining prism with a groove, including a beam combining prism 30 that is optically bonded to the reflector 20 of the laser gyroscope cavity 10 by an optical adhesive surface 31, used to combine two laser beams propagating clockwise and counterclockwise within the laser gyroscope cavity 10 for optical interference; the optical adhesive surface 31 has a groove 32, and a semi-transparent and semi-reflective film 33 is deposited in the groove to reduce the loss of the laser beam; wherein, the depth of the groove is greater than or equal to the thickness of the semi-transparent and semi-reflective film 33; a phototube 40 is bonded to the output end face of the beam combining prism 30 for detecting the interference signal generated by the two laser beams propagating clockwise and counterclockwise within the laser gyroscope ring resonant cavity 10.

[0035] Applying the technical solution of this embodiment, two laser beams propagating clockwise and counterclockwise from the ring resonant cavity 10 of the laser gyroscope enter the optical adhesive surface of the reflector 20 and the optical combining prism 30. After multiple reflections, they form optical interference and enter the phototube 40 from the exit end face of the optical combining prism 30. The phototube 40, through the sensitive optical interference signal, outputs a photocurrent signal with a frequency consistent with the frequency difference between the clockwise and counterclockwise laser beams. At the positions where the clockwise and counterclockwise laser beams pass through the optical adhesive surface of the optical combining prism 30, there are etched pits 32. The pits are coated with a semi-transparent and semi-reflective film 33 with a thickness less than or equal to the pit depth. The film layer is lower than the optical adhesive surface to reduce the loss generated when the laser beam passes through, thereby increasing the optical adhesive area, enhancing the affinity of the optical adhesive interface between the same materials, reducing the optical adhesive stress, and improving the reliability of the optical combining prism and the performance of the gyroscope under harsh operating conditions.

[0036] Specifically, the optical combining prism 30 is bonded to the reflector 20 of the laser gyroscope ring resonator 10 by optical adhesive method, which can increase the optical adhesive area, improve the optical adhesive strength and reliability of use.

[0037] like Figure 2 As shown, the roughness of groove 32 is no greater than 5nm, so as to avoid excessive roughness reducing the light transmittance.

[0038] Optionally, the semi-transparent and semi-reflective film 33 has a reflectivity to transmittance ratio of 1:1.

[0039] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A laser gyroscope beam-combining prism with a groove, characterized in that, include: The optical combining prism (30) is bonded to the reflector (20) of the laser gyroscope ring resonator (10) by optical adhesive; The optical adhesive surface of the optical combining prism (30) has a groove, and a semi-transparent and semi-reflective film is coated in the groove.

2. The grooved laser gyroscope beam-combining prism according to claim 1, characterized in that, The groove is located where the laser passes through, and the groove can be circular, square, or U-shaped.

3. A grooved laser gyroscope beam-combining prism according to claim 1, characterized in that, The surface roughness (RMS) of the bottom surface of the groove is no greater than 5 nm, and the flatness of the bottom surface of the groove is no greater than 60 nm.

4. A grooved laser gyroscope beam-combining prism according to claim 1, characterized in that, The groove depth is greater than or equal to the thickness of the semi-permeable and semi-reflective film layer.

5. A grooved laser gyroscope beam-combining prism according to claim 1, characterized in that, The diameter or width of the groove is greater than the diameter or width of the semi-permeable and semi-reflective membrane.

6. A grooved laser gyroscope beam-combining prism according to claim 1, characterized in that, The semi-transparent and semi-reflective film is deposited at the center of the groove.

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