Coupling method of fiber-optic gyroscope

Abstract

The invention discloses a coupling method of a fiber-optic gyroscope, which comprises the following steps: fixing a circulator on a TEC thermoelectric refrigerating unit, and fixing the TEC thermoelectric refrigerating unit in a shell; the light receiving assembly is fixed to the TEC thermoelectric refrigerating unit, and the light emitting assembly is matched with the first cushion block to be fixed in the shell; coupling the Y waveguide and the optical fiber assembly outside the shell, and fixing the Y waveguide and the optical fiber assembly on a second cushion block; coupling a first collimating lens with the Y waveguide and the optical fiber assembly, and fixing the first collimating lens on a second cushion block; the second cushion block is fixed in the shell; a second collimating lens is coupled with the light emitting assembly, the circulator, the first collimating lens, the Y waveguide and the optical fiber assembly, and the second collimating lens is fixed to the TEC thermoelectric refrigerating unit; a third collimating lens is coupled with the light receiving assembly, the circulator, the first collimating lens, the Y waveguide and the optical fiber assembly, and the third collimating lens is fixed to the TEC thermoelectric refrigerating unit. The coupling efficiency can be effectively improved, and the effects of stable measurement and high-precision measurement are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to a coupling method of a fiber optic gyroscope. Background Art

[0002] Fiber Optic Gyroscope (FOG), also known as fiber optic angular velocity sensor or fiber optic gyroscope (FOG), is a fiber optic sensor used for inertial navigation. Fiber optic gyroscope is a solid-state gyroscope without mechanical moving parts, with the advantages of no warm-up time, insensitive to acceleration, wide dynamic range, digital output, and small size.

[0003] Fiber optic gyroscopes are widely used in aerospace, including navigation, attitude control and stabilization systems of aircraft. In addition, fiber optic gyroscopes are also widely used in defense, aerospace, celestial motion observation, unmanned carriers (robots, drones, etc.) and other autonomous intelligent systems. With the development of technology, the application scope of fiber optic gyroscopes is gradually expanding to civil fields such as oil exploration, intelligent transportation, mobile satellite communications, railway track measurement, and marine engineering.

[0004] The working principle of fiber optic gyroscope is mainly based on the Sagnac effect. When a light beam travels in a circular channel, if the circular channel itself has a rotation speed, the time required for the light to travel along the direction of the channel rotation is longer than the time required to travel along the opposite direction of the channel rotation. By using this change in the optical path, the phase difference or interference fringes of the two light paths can be detected, and the angular velocity of the light path rotation can be measured.

[0005] The internal structure of the fiber optic gyroscope is relatively complex, involving many optical paths. The coupling sequence of the various components of the fiber optic gyroscope has a crucial impact on the performance, stability and reliability of the fiber optic gyroscope. Therefore, when designing and manufacturing the fiber optic gyroscope, it must be assembled and debugged strictly in accordance with a reasonable coupling sequence to ensure that the fiber optic gyroscope can achieve the expected performance indicators and service life, and achieve stable measurement and high-precision measurement results. Summary of the invention

[0006] In order to improve coupling efficiency and achieve stable measurement and high-precision measurement effects, the present invention provides a coupling method for a fiber optic gyroscope.

[0007] An embodiment of the present invention provides a coupling method of a fiber optic gyroscope, comprising the following steps:

[0008] Fixing the circulator to the TEC thermoelectric cooler, and fixing the TEC thermoelectric cooler in a housing;

[0009] Based on the position of the circulator, determine the positions of the light receiving component and the light emitting component, fix the light receiving component to the TEC thermoelectric cooler, and fix the light emitting component in the housing in cooperation with the first pad;

[0010] Outside the housing, placing a Y-waveguide and an optical fiber assembly on a second pad, placing the optical fiber assembly on a light-emitting side of the Y-waveguide, coupling the Y-waveguide and the optical fiber assembly, and fixing the Y-waveguide and the optical fiber assembly on the second pad;

[0011] Placing a first collimating lens at a preset position close to the light incident side of the Y-waveguide, coupling the first collimating lens with the Y-waveguide and the optical fiber assembly, and fixing the first collimating lens to the second spacer;

[0012] Based on the annulator, fixing the second cushion block in the housing;

[0013] placing a second collimating lens between the light emitting assembly and the circulator, coupling the second collimating lens with the light emitting assembly, the circulator, the first collimating lens, the Y-waveguide and the optical fiber assembly, and fixing the second collimating lens to the TEC thermoelectric cooler;

[0014] A third collimating lens is placed between the light receiving component and the circulator, the third collimating lens is coupled with the light receiving component, the circulator, the first collimating lens, the Y waveguide and the optical fiber component, and the third collimating lens is fixed to the TEC thermoelectric cooler.

[0015] Optionally, the coupling method of the Y-waveguide and the optical fiber assembly includes:

[0016] A light source is arranged at the light incident side of the Y-waveguide, the insertion loss of the Y-waveguide and the optical fiber component coupled output is monitored, and the position of the Y-waveguide or the optical fiber component is adjusted until the insertion loss reaches a preset insertion loss value.

[0017] Optionally, the preset insertion loss value is 0.2dB-0.4dB.

[0018] Optionally, the coupling method of the first collimating lens, the Y-waveguide and the optical fiber assembly includes:

[0019] A light source is arranged at one end of the optical fiber assembly away from the Y-waveguide, and the light source sequentially passes through the optical fiber assembly, the Y-waveguide and the first collimating lens;

[0020] A beam quality analyzer is used to detect the light spot quality of the light source after passing through the first collimating lens, and the position of the first collimating lens is fine-tuned until the light spot quality meets the preset requirements.

[0021] Optionally, the light spot quality includes a light spot diameter;

[0022] The step of using a beam quality analyzer to detect the light spot quality of the light source after passing through the first collimating lens, and fine-tuning the position of the first collimating lens until the light spot quality meets a preset requirement includes:

[0023] Setting a proximal detection point and a distal detection point as detection points of the beam quality analyzer, wherein a distance between the proximal detection point and the Y waveguide is smaller than a distance between the distal detection point and the Y waveguide, and the first collimating lens is located between the proximal detection point and the Y waveguide;

[0024] The beam quality analyzer is used to respectively detect the spot diameters at the proximal detection point and the distal detection point, and the position of the first collimating lens is fine-tuned until the spot diameter meets preset requirements, wherein the preset requirements include that the spot diameter at the proximal detection point is 200μm-340μm, and the spot diameter at the distal detection point is 800μm-1000μm.

[0025] Optionally, a method for coupling the second collimating lens with the light emitting assembly, the circulator, the first collimating lens, the Y-waveguide and the optical fiber assembly includes:

[0026] The light emitting component excites emission light, and the emission light is sequentially transmitted by the second collimating lens, the circulator, the first collimating lens, and the Y-waveguide, and is output from the output port of the optical fiber component;

[0027] An optical power meter is connected to the output port of the optical fiber assembly to monitor the optical power of the optical fiber assembly in real time, and the position of the second collimating lens is adjusted until the optical power reaches a preset power value.

[0028] Optionally, the preset power value is 0.9mw-1.1mw.

[0029] Optionally, a method for coupling the third collimating lens with the light receiving component, the circulator, the first collimating lens, the Y-waveguide and the optical fiber component includes:

[0030] A light source is arranged at one end of the optical fiber assembly away from the Y-waveguide, and the light source is transmitted to the light receiving assembly by the optical fiber assembly, the Y-waveguide, the first collimating lens, the circulator, and the third collimating lens;

[0031] The responsiveness of the light receiving component is detected, and the position of the third collimating lens is adjusted until the responsiveness reaches a preset responsiveness, and the third collimating lens is fixed to the TEC thermoelectric cooler.

[0032] Optionally, the preset responsiveness is 0.5mw-0.7mw.

[0033] The beneficial effects of the above technical solution provided in the embodiments of the present invention include at least:

[0034] In an embodiment of the present invention, a coupling method for a fiber optic gyroscope is provided. The position of a circulator is first determined and fixed in a housing to ensure that subsequent optical signals are not distorted due to path errors or interference during transmission; then, based on the position of the circulator, the positions of an optical receiving component and an optical transmitting component are determined and fixed in the housing; then, outside the housing, a Y-waveguide and an optical fiber component are first coupled, and then a first collimating lens is coupled with the Y-waveguide and the optical fiber component, so that the first collimating lens, the Y-waveguide and the optical fiber component form a whole, achieving the function of a collimating device, facilitating a subsequent coupling process, and effectively improving the coupling efficiency; finally, the second collimating lens and the third collimating lens are coupled in sequence.

[0035] Through the coupling method of this embodiment, a reasonable coupling sequence is formed, which can ensure the stable transmission of the optical signal inside the fiber optic gyroscope, reduce signal interference and loss, thereby improving the accuracy and stability of the fiber optic gyroscope, and ensuring the high coupling efficiency of each component. At the same time, a reasonable coupling sequence can optimize the signal transmission path, minimize the interference of the optical signal during the transmission process, and ensure the accuracy and stability of the fiber optic gyroscope. And through the coupling method of this embodiment, the fiber optic gyroscope is divided into three independent modules: the Y waveguide, the first collimating lens and the optical fiber assembly fixed to the second pad form the first module; the circulator, the optical transmitting assembly, the second collimating lens and the third collimating lens fixed to the TEC thermoelectric cooler form the second module; the optical receiving assembly fixed to the first pad forms the third module, so that the various components of the fiber optic gyroscope are modularized, which is convenient for maintenance and upgrading. When a component fails or needs to be upgraded, it can be easily removed from the system and replaced or upgraded without affecting the normal operation of other components.

[0036] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0037] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 A flow chart of the coupling method of the fiber optic gyroscope provided in this embodiment;

[0040] Figure 2 This is a schematic diagram of the structure of the fiber optic gyroscope provided in this embodiment;

[0041] Description of the accompanying drawings:

[0042] 1. Shell; 2. Light emitting component; 3. Light receiving component; 4. circulator; 5. Y waveguide; 51. Dual input port; 52. Single input port; 6. First collimating lens; 7. Second collimating lens; 8. Third collimating lens; 9. Optical fiber component; 91. Bare fiber end; 92. Optical fiber pad; 93. Optical fiber; 10. TEC thermoelectric cooler; 11. First pad; 12. Second pad. DETAILED DESCRIPTION

[0043] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0044] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "far", "near", "front", "back" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The inventors have discovered that the coupling sequence of the components of the existing fiber optic gyroscope is not set reasonably, and the coupling efficiency between the components is low, which causes unnecessary interference to the optical signal during transmission, resulting in a deviation between the final detected signal and the actual angular velocity change, thereby reducing the accuracy and stability of the fiber optic gyroscope, and forming a more complex connection relationship between the components of the fiber optic gyroscope, reducing the modularity of the fiber optic gyroscope, and increasing the difficulty of maintenance and upgrading.

[0047] In order to solve the above problems, the inventors proposed a coupling method for a fiber optic gyroscope to ensure that the components of the fiber optic gyroscope are coupled in a reasonable coupling order, thereby ensuring the accuracy and stability of the fiber optic gyroscope.

[0048] The embodiment of the present application provides a coupling method of a fiber optic gyroscope, which is applied to a fiber optic gyroscope, wherein the fiber optic gyroscope includes a housing, a first cushion block, a second cushion block, a circulator, a TEC thermoelectric cooler, a light receiving component, a light transmitting component, a Y waveguide, an optical fiber component, a first collimating lens, a second collimating lens, and a third collimating lens. Figure 1 The coupling method of the fiber optic gyroscope of this embodiment includes the following steps:

[0049] Step S1, fixing the circulator to the TEC thermoelectric cooler, and fixing the TEC thermoelectric cooler in a housing;

[0050] Step S2, based on the position of the circulator, determine the positions of the light receiving component and the light emitting component, fix the light receiving component to the TEC thermoelectric cooler, and fix the light emitting component in the housing with the first pad;

[0051] Step S3, outside the housing, placing the Y-waveguide and the optical fiber assembly on the second pad, placing the optical fiber assembly on the light-emitting side of the Y-waveguide, coupling the Y-waveguide and the optical fiber assembly, and fixing the Y-waveguide and the optical fiber assembly on the second pad;

[0052] Step S4, placing the first collimating lens at a preset position close to the light incident side of the Y waveguide, coupling the first collimating lens with the Y waveguide and the optical fiber assembly, and fixing the first collimating lens to the second pad;

[0053] Step S5, fixing the second cushion block in the housing based on the position of the circulator;

[0054] Step S6, placing the second collimating lens between the light emitting assembly and the circulator, coupling the second collimating lens with the light emitting assembly, the circulator, the first collimating lens, the Y waveguide and the optical fiber assembly, and fixing the second collimating lens to the TEC thermoelectric cooler;

[0055] Step S7, placing the third collimating lens between the light receiving assembly and the circulator, coupling the third collimating lens with the light receiving assembly, the circulator, the first collimating lens, the Y waveguide and the optical fiber assembly, and fixing the third collimating lens to the TEC thermoelectric cooler.

[0056] In order to explain the coupling method of the fiber optic gyroscope more clearly, each step is described in detail below.

[0057] In the above step S1, since the circulator plays an important role in the fiber optic gyroscope system, it is usually used to control the transmission direction of the optical signal to ensure that the optical signal flows along a predetermined path inside the fiber optic gyroscope. By pre-fixing the position of the circulator, it can be ensured that the subsequent optical signal will not be distorted due to path errors or interference during the transmission process, and the loss of the optical signal during the transmission process can be reduced, thereby improving the accuracy and stability of signal transmission.

[0058] In the above step S2, the circulator has three ports, including a first port, a second port and a third port, wherein the second port is arranged toward the optical transmitting component, and the third port is arranged toward the optical receiving component, and the positions of the optical receiving component and the optical transmitting component are determined based on the positions of the second port and the third port of the circulator. The optical receiving component is fixed to the TEC thermoelectric cooler, and a corresponding height pad can be set as required to match the height of the optical path. The optical transmitting component is fixed to the first pad, and the first pad is fixed in the housing.

[0059] In the above step S3, the Y-waveguide and the optical fiber assembly are first coupled outside the housing, so that the Y-waveguide and the optical fiber assembly can be more conveniently finely adjusted to ensure that the alignment accuracy between them is optimal, thereby reducing coupling loss and improving the transmission efficiency of optical signals. In addition, since the environment inside the housing may be complex and changeable, there are interference factors such as temperature and vibration, which may affect the stability and accuracy of the coupling. Coupling outside the housing can minimize these interferences and improve the reliability of the coupling.

[0060] The coupling method of the Y-waveguide and optical fiber assembly may include the following steps:

[0061] A light source is set on the light incident side of the Y-waveguide, and a high-resolution optical link diagnostic instrument (OCI) or other suitable equipment in the prior art can be used to monitor the insertion loss of the coupled output of the Y-waveguide and the optical fiber component, and adjust the position of the Y-waveguide or the optical fiber component until the insertion loss reaches a preset insertion loss value, which is 0.2dB-0.4dB.

[0062] Since the materials of the optical fiber assembly and the Y-waveguide themselves will have certain absorption and scattering losses, which are determined by the physical properties of the materials themselves, these losses cannot be completely eliminated (i.e., the insertion loss is inevitably 0.2dB), and if the insertion loss is too large (i.e., the insertion loss is greater than 0.4dB), it will cause the light beam to be severely attenuated during the transmission process, affecting the overall performance of the system. Through multiple experiments, the inventor controlled the insertion loss of the coupled output of the two to 0.2dB-0.4dB, which can significantly improve the transmission efficiency and receiving sensitivity, reduce the bit error rate, and thus achieve efficient coupling efficiency. After coupling, use optical glue to fix the Y-waveguide and the optical fiber assembly to the second pad. During the fixing process, due to the small distance between the Y-waveguide and the optical fiber assembly, it is difficult to dispense glue, and the amount of glue needs to be controlled to avoid overflow of the optical glue and affect the coupling between the two.

[0063] In the above step S4, the first collimating lens is placed at a preset position close to the light incident side of the Y waveguide, and the first collimating lens is coupled using the following method:

[0064] Step S41, a light source is arranged at one end of the optical fiber assembly away from the Y waveguide, and the light source passes through the optical fiber assembly, the Y waveguide and the first collimating lens in sequence;

[0065] Step S42: Use a beam quality analyzer to detect the light spot quality of the light source after passing through the first collimating lens, and fine-tune the position of the first collimating lens until the light spot quality meets the preset requirements.

[0066] In the above step S42, the spot diameter may be used as a basis for evaluating the spot quality. The process of detecting the spot quality with a beam quality analyzer may include:

[0067] Step S421, setting a proximal detection point and a distal detection point as detection points of the beam quality analyzer, wherein the distance between the proximal detection point and the Y waveguide is smaller than the distance between the distal detection point and the Y waveguide, and the first collimating lens is between the proximal detection point and the Y waveguide.

[0068] In the above step S421, since the size of the spot diameter is directly related to the divergence and collimation effect of the light beam, it further affects the coupling efficiency between the Y waveguide and the first collimating lens. By detecting the spot diameter at two observation points (the near-end detection point and the far-end detection point), the change of the light beam during propagation can be intuitively understood, thereby evaluating the coupling effect. Here, the near-end detection point is set at a distance of 18 mm from the Y waveguide, and the far-end detection point is set at a distance of 170 mm from the Y waveguide.

[0069] Step S422, using a beam quality analyzer to detect the spot diameters at the near-end detection point and the far-end detection point respectively, and fine-tuning the position of the first collimating lens until the spot diameter meets the preset requirements, wherein the preset requirements include that the spot diameter at the near-end detection point is 200μm-340μm, and the spot diameter at the far-end detection point is 800μm-1000μm. If the spot is too large or too small, part of the light energy may not be effectively coupled into the Y waveguide or the first collimating lens, thereby reducing the overall light transmission efficiency. Only when the spot diameter meets the above preset requirements can the best light transmission effect be achieved, thereby ensuring the best coupling efficiency.

[0070] Then, the coupled first collimating lens is fixed to the second pad. The first collimating lens can form a whole with the optical fiber assembly and the Y waveguide to achieve the function of a collimating device, facilitate the subsequent coupling process, and effectively improve the coupling efficiency.

[0071] In the above step S5, based on the position of the circulator, specifically, the first collimating lens is disposed close to the first port of the circulator, and the second gasket is fixed in the housing.

[0072] In the above step S6, the coupling method of the second collimating lens with the light emitting assembly, the circulator, the first collimating lens, the Y-waveguide and the optical fiber assembly may include the following steps:

[0073] Step S61, the light emitting component excites the emission light, and the emission light is transmitted in sequence by the second collimating lens, the circulator, the first collimating lens, and the Y waveguide, and is output from the output port of the optical fiber component;

[0074] Step S62: Connect an optical power meter to the output port of the optical fiber assembly, monitor the optical power of the optical fiber assembly in real time, and adjust the position of the second collimating lens until the optical power reaches a preset power value.

[0075] In the above step S62, the purpose of coupling the second collimating lens is to efficiently couple the emission light excited by the emission component into the optical fiber component, reducing the loss of light during the coupling process. By detecting the optical power of the output port of the optical fiber component, the coupling efficiency can be intuitively evaluated. In this embodiment, the above preset power value is set to 0.9mw-1.1mw. When the optical power is too high (i.e., greater than 1.1mw), nonlinear effects may be caused. These nonlinear effects will destroy the integrity of the optical signal, causing signal distortion and noise increase, thereby reducing the measurement accuracy and stability of the fiber optic gyroscope, and excessive optical power may cause excessive heat to be generated inside the optical fiber component, thereby damaging the optical fiber component and affecting other optical devices connected to the optical fiber component, thereby affecting the overall stability of the fiber optic gyroscope; when the optical power is too low (i.e., less than 0.9mw), the optical signal may be rapidly attenuated during the transmission process, and cannot be effectively received and processed by other subsequent components, resulting in a decrease in the overall efficiency of the fiber optic gyroscope, and the performance advantages of each component cannot be fully utilized.

[0076] In the above step S7, the coupling method of the third collimating lens with the light receiving component, the circulator, the first collimating lens, the Y waveguide and the optical fiber component includes the following steps:

[0077] Step S71, a light source is arranged at one end of the optical fiber assembly away from the Y waveguide, and the light source is transmitted to the light receiving assembly through the optical fiber assembly, the Y waveguide, the first collimating lens, the circulator, and the third collimating lens;

[0078] Step S71 , detecting the responsivity of the light receiving component, adjusting the position of the third collimating lens until the responsivity reaches a preset responsivity, and fixing the third collimating lens to the TEC thermoelectric cooler.

[0079] In this embodiment, the preset responsivity is 0.5mw-0.7mw. Responsivity is an important indicator, which reflects the ability of the photodetector to convert optical signals into electrical signals. If the responsivity of the optical receiving component is too low (i.e., the responsivity is less than 0.5mw), the optical signal cannot be captured accurately and sensitively. If the responsivity is too high (i.e., the responsivity is greater than 0.7mw), it will cause problems such as signal distortion and noise amplification. Therefore, when the responsivity of the optical receiving component is between 0.5mw and 0.7mw, it can ensure that the measurement accuracy, stability and dynamic range of the entire fiber optic gyroscope meet the requirements.

[0080] In this embodiment, the position of the circulator is first determined and fixed in the housing to ensure that the subsequent optical signal will not be distorted due to path errors or interference during transmission; then, based on the position of the circulator, the positions of the optical receiving component and the optical transmitting component are determined and fixed in the housing; then, outside the housing, the Y-waveguide and optical fiber components are first coupled, and then the first collimating lens is coupled with the Y-waveguide and optical fiber components, so that the first collimating lens, the Y-waveguide and the optical fiber components form a whole, achieving the function of a collimating device, facilitating the subsequent coupling process, and effectively improving the coupling efficiency; finally, the second collimating lens and the third collimating lens are coupled in turn.

[0081] Through the coupling method of this embodiment, a reasonable coupling sequence is formed, which can ensure the stable transmission of the optical signal inside the fiber optic gyroscope, reduce signal interference and loss, thereby improving the accuracy and stability of the fiber optic gyroscope, and ensuring the high coupling efficiency of each component. At the same time, a reasonable coupling sequence can optimize the signal transmission path, minimize the interference of the optical signal during the transmission process, and ensure the accuracy and stability of the fiber optic gyroscope. And through the coupling method of this embodiment, the fiber optic gyroscope is divided into three independent modules: the Y waveguide, the first collimating lens and the optical fiber assembly fixed to the second pad form the first module; the circulator, the optical transmitting assembly, the second collimating lens and the third collimating lens fixed to the TEC thermoelectric cooler form the second module; the optical receiving assembly fixed to the first pad forms the third module, so that the various components of the fiber optic gyroscope are modularized, which is convenient for maintenance and upgrading. When a component fails or needs to be upgraded, it can be easily removed from the system and replaced or upgraded without affecting the normal operation of other components.

[0082] According to the coupling method of this embodiment, the coupled fiber optic gyroscope is as follows: Figure 2 As shown, the Y-waveguide 5, the first collimating lens 6 and the optical fiber assembly 9 are fixed to the second pad 12; the circulator 4, the optical transmitting assembly 2, the second collimating lens 7 and the third collimating lens 8 are fixed to the TEC thermoelectric cooler 10; and the optical receiving assembly 3 is fixed to the first pad 11.

[0083] The Y-waveguide 5 includes a single input end 52 and a double input end 51. Figure 1The Y-type shown in . The optical fiber component 9 is arranged at the dual input end 51 of the Y waveguide 5. The circulator 4 includes three ports, namely a first port (not marked in the figure), a second port (not marked in the figure) and a third port (not marked in the figure), wherein the first port of the circulator 4 is arranged toward the single input end 52 of the Y waveguide 5, and a first collimating lens 6 is arranged between the first port of the circulator 4 and the single input end 52 of the Y waveguide 5; the second port of the circulator 4 is arranged toward the optical transmitting component 2, and a second collimating lens 7 is arranged between the second port of the circulator 4 and the optical transmitting component 2; the third port of the circulator 4 is arranged toward the optical receiving component 3, and a third collimating lens 8 is arranged between the third port of the circulator 4 and the optical receiving component 3.

[0084] When in use, the emission light path is: the light emitting component 2 excites the emission light, the emission light is collimated into parallel light by the second collimating lens 7, and then transmitted to the second port of the circulator 4, and is transmitted out through the first port of the circulator 4, and is converged to the single input end 52 of the Y waveguide 5 by the first collimating lens 6, and is output from the double input end 51 of the Y waveguide 5 to the optical fiber component 9.

[0085] The receiving optical path is as follows: the light beam transmitted back from the optical fiber component 9 is input through the dual input end 51 of the Y waveguide 5, output from the single input end 52 of the Y waveguide 5, is collimated into parallel light by the first collimating lens 6, is input from the first port of the circulator 4, and is output from the third port of the circulator 4, is converged back to the light receiving component 3 through the third collimating lens 8, and is received by the light receiving component 3.

[0086] In this embodiment, the fiber optic gyroscope components are not connected by optical fiber fusion, but by spatial optical transmission, which can effectively avoid the problems of multiple fusion points, large loss, and low coupling efficiency of the fiber optic gyroscope in the prior art. At the same time, the components of the fiber optic gyroscope are integrated in the housing, which can effectively simplify the assembly process and has the characteristics of low insertion loss and high integration.

[0087] Of course, the centralized design of the various components of the fiber optic gyroscope in the shell 1 also has the following advantages: the fiber optic gyroscope is used as an integral unit to optimize the overall performance and facilitate calibration and testing; it helps to reduce the impact of external electromagnetic interference on the various components in the shell, thereby maintaining the purity and stability of the signal and achieving a compact structure; the relative positions of the various components are made more stable, reducing the coupling error caused by relative movement or misalignment between the components; the compact structure helps to reduce the overall size and reduce the interference of the external environment on the internal components, thereby improving the stability of the system; the centralized design allows for more precise control of the thermal properties of the shell, such as thermal conductivity, density and specific heat capacity, thereby optimizing the thermal stability of the fiber optic gyroscope. A stable temperature environment is essential for reducing thermal noise and temperature drift, which are important factors affecting the coupling effect; the connection and fit between the components are optimized in the centrally designed shell, reducing the risk of failure due to poor connection or improper fit, thereby improving the reliability of the fiber optic gyroscope.

[0088] In a specific embodiment, the optical fiber assembly 9 includes an optical fiber spacer 92 and an optical fiber 93. A bare fiber end 91 is provided at one end of the optical fiber 93. The bare fiber end 91 is coupled with the dual input end 51, and the bare fiber end 91 can be fixed to the optical fiber spacer 92. Specifically, after the bare fiber end 91 is coupled with the dual input end 51 of the Y waveguide 5, the coupling method can refer to the above-mentioned step S3, which will not be repeated here, and the coupled bare fiber end 91 can be fixed to the optical fiber spacer 92.

[0089] In this embodiment, by fixing the bare fiber end on the fiber pad, it is possible to ensure that the optical fiber maintains a stable position, reducing the risk of fiber breakage or performance degradation due to movement or vibration; and by fixing the bare fiber end, the influence of external forces on the optical fiber can be effectively reduced, and the stress on the straightness and stability of the optical fiber can be maintained, thereby ensuring its optical transmission performance. Fixing the bare fiber end on the fiber pad makes it easier to achieve precise alignment with the Y-waveguide or other optical devices, thereby improving coupling efficiency and reducing optical signal loss. Furthermore, fixing the bare fiber end on the side wall or top surface of the fiber pad can achieve a more compact equipment design, saving valuable space resources.

[0090] In a specific embodiment, see Figure 2 , a light emitting assembly 2, a second collimating lens 7, a first collimating lens 6 and a circulator 4 are provided on the TEC thermoelectric cooler 10. In order to match the optical path heights of the light emitting assembly 2, the second collimating lens 7 and the circulator 4, a plurality of height matching pads (not shown in the figure) can be provided on the TEC thermoelectric cooler 10 for use in conjunction with the light emitting assembly 2.

[0091] In this embodiment, since the light emitting component generates heat when working, if the heat cannot be dissipated in time, the temperature of the light emitting component will exceed the set threshold, causing the wavelength of the light beam excited by the light emitting component to fail to meet the requirements of stability and accuracy. Therefore, a thermistor can be set near the light emitting component 2, and the output signal of the thermistor can be connected to the TEC thermoelectric cooler, which can realize the automation of temperature monitoring and control, and improve the accuracy and efficiency of temperature control, thereby ensuring that the light emitting component 2 is always in a suitable temperature environment.

[0092] In a specific embodiment, see Figure 2 , the optical receiving component 3 includes a PD chip, so that the PD chip is set directly opposite the third collimating lens 8, and there is no need to set a separate reflector to reflect to match the optical path, that is, in the receiving optical path, the light beam transmitted back from the optical fiber component 9 can directly irradiate the PD chip after passing through the third collimating lens 8, without the need for an additional reflector for turning, which can effectively reduce the number of reflections of the light beam during the propagation process and the loss caused by optical elements (such as reflectors), thereby improving the receiving efficiency of the optical signal and the overall performance of the system. Removing the reflector makes the entire optical system more compact, which is conducive to realizing a more complex optical layout in a limited space, and achieves the effect of simplifying the structure, reducing the number and complexity of optical elements, and reducing the difficulty and cost of assembling the system.

[0093] In a specific embodiment, a switching circuit (not shown in the figure) is provided in the housing 1, and the switching circuit connects the pins of the housing 1 and the electrodes of the Y waveguide 5 respectively, so that the electrodes of the Y waveguide 5 are electrically connected to the corresponding pins of the housing 1, and the input of signals and power is provided to the Y waveguide 5. The external circuit is connected to the Y waveguide 5 through the pins of the housing 1, so that the signal sent by the external circuit is transmitted to the Y waveguide 5, and the Y waveguide 5 device is driven to perform corresponding optical modulation. By electrically connecting the electrodes of the Y waveguide 5 to the corresponding pins of the housing 1, it can be ensured that the signal is accurately and quickly transmitted from the external circuit to the Y waveguide 5, and the modulation of the optical signal is realized. At the same time, the Y waveguide 5 can be integrated with the external circuit to form a complete module. This integrated design can reduce the volume of the entire system and improve the integration of the system. In addition, by electrically connecting the electrodes of the Y waveguide 5 to the corresponding pins of the housing 1, the electric energy of the external power supply can also be transmitted to the Y waveguide 5 to ensure its normal operation.

[0094] In a specific embodiment, the optical emission component 2 can be arranged on a side close to the pin, which can be conveniently connected to external circuits and devices, improve the convenience of assembly and connection, and at the same time, reduce the loss and interference of external circuits and devices during a long transmission process, and improve the efficiency of transmission. The optical emission component 2 will generate a certain amount of heat when working. The optical emission component 2 is arranged on a side close to the pin, which can better manage heat, and the heat can be exported through the pin to prevent the optical emission component 2 from overheating.

[0095] Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various changes and modifications may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. Thus, if these changes and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A coupling method for a fiber optic gyroscope, characterized in that: The following steps are involved: Fixing the circulator to the TEC thermoelectric cooler, and fixing the TEC thermoelectric cooler in a housing; Based on the position of the circulator, determine the positions of the light receiving component and the light emitting component, fix the light receiving component to the TEC thermoelectric cooler, and fix the light emitting component in the housing in cooperation with the first pad; Outside the housing, placing a Y-waveguide and an optical fiber assembly on a second pad, placing the optical fiber assembly on a light-emitting side of the Y-waveguide, coupling the Y-waveguide and the optical fiber assembly, and fixing the Y-waveguide and the optical fiber assembly on the second pad; Placing a first collimating lens at a preset position close to the light incident side of the Y-waveguide, coupling the first collimating lens with the Y-waveguide and the optical fiber assembly, and fixing the first collimating lens to the second spacer; fixing the second pad in the housing based on the position of the circulator; placing a second collimating lens between the light emitting assembly and the circulator, coupling the second collimating lens with the light emitting assembly, the circulator, the first collimating lens, the Y-waveguide and the optical fiber assembly, and fixing the second collimating lens to the TEC thermoelectric cooler; A third collimating lens is placed between the light receiving component and the circulator, the third collimating lens is coupled with the light receiving component, the circulator, the first collimating lens, the Y waveguide and the optical fiber component, and the third collimating lens is fixed to the TEC thermoelectric cooler.

2. The coupling method of the fiber optic gyroscope according to claim 1, characterized in that: The coupling method of the Y-waveguide and the optical fiber assembly comprises: A light source is arranged at the light incident side of the Y-waveguide, the insertion loss of the Y-waveguide and the optical fiber component coupled output is monitored, and the position of the Y-waveguide or the optical fiber component is adjusted until the insertion loss reaches a preset insertion loss value.

3. The coupling method of the fiber optic gyroscope according to claim 2, characterized in that: The preset insertion loss value is 0.2dB-0.4dB.

4. The coupling method of the fiber optic gyroscope according to claim 1, characterized in that: The coupling method of the first collimating lens with the Y-waveguide and the optical fiber assembly comprises: A light source is arranged at one end of the optical fiber assembly away from the Y-waveguide, and the light source sequentially passes through the optical fiber assembly, the Y-waveguide and the first collimating lens; A beam quality analyzer is used to detect the light spot quality of the light source after passing through the first collimating lens, and the position of the first collimating lens is fine-tuned until the light spot quality meets the preset requirements.

5. The coupling method of the fiber optic gyroscope according to claim 4, characterized in that: The light spot quality includes the light spot diameter; The step of using a beam quality analyzer to detect the light spot quality of the light source after passing through the first collimating lens, and fine-tuning the position of the first collimating lens until the light spot quality meets a preset requirement includes: Setting a proximal detection point and a distal detection point as detection points of the beam quality analyzer, wherein a distance between the proximal detection point and the Y waveguide is smaller than a distance between the distal detection point and the Y waveguide, and the first collimating lens is located between the proximal detection point and the Y waveguide; The beam quality analyzer is used to respectively detect the spot diameters at the proximal detection point and the distal detection point, and the position of the first collimating lens is fine-tuned until the spot diameter meets preset requirements, wherein the preset requirements include that the spot diameter at the proximal detection point is 200μm-340μm, and the spot diameter at the distal detection point is 800μm-1000μm.

6. The coupling method of the fiber optic gyroscope according to claim 1, characterized in that: The coupling method of the second collimating lens with the light emitting assembly, the circulator, the first collimating lens, the Y-waveguide and the optical fiber assembly comprises: The light emitting component excites emission light, and the emission light is sequentially transmitted by the second collimating lens, the circulator, the first collimating lens, and the Y-waveguide, and is output from the output port of the optical fiber component; An optical power meter is connected to the output port of the optical fiber assembly to monitor the optical power of the optical fiber assembly in real time, and the position of the second collimating lens is adjusted until the optical power reaches a preset power value.

7. The coupling method of the fiber optic gyroscope according to claim 6, characterized in that: The preset power value is 0.9mw-1.1mw.

8. The coupling method of the fiber optic gyroscope according to claim 1, characterized in that: The coupling method of the third collimating lens with the light receiving component, the circulator, the first collimating lens, the Y-waveguide and the optical fiber component comprises: A light source is arranged at one end of the optical fiber assembly away from the Y-waveguide, and the light source is transmitted to the light receiving assembly by the optical fiber assembly, the Y-waveguide, the first collimating lens, the circulator, and the third collimating lens; The responsivity of the light receiving component is detected, and the position of the third collimating lens is adjusted until the responsivity reaches a preset responsivity, and the third collimating lens is fixed to the TEC thermoelectric cooler.

9. The coupling method of the fiber optic gyroscope according to claim 8, characterized in that: The preset responsiveness is 0.5mw-0.7mw.

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