An encapsulated integrated fiber optic gyroscope structure and its manufacturing method

Abstract

The present invention relates to the technical field of inertial measurement devices, and specifically discloses a packaged integrated fiber optic gyroscope structure and a manufacturing method thereof. The structure comprises a substrate and an optical coupling chip arranged on the substrate, an optical modulation chip, an optical fiber ring connected to the optical modulation chip, a laser functional mirror group connected to the optical coupling chip for emitting laser light, an optical detection chip, and a circuit processing module for ensuring normal operation of the fiber optic gyroscope. The optical modulation chip adopts a straight-arm modulator, and the optical coupling chip comprises a transmission waveguide, a first 3dB coupler connected to the optical modulation chip, and a second 3dB coupler connected to the laser functional mirror group. The optical modulation chip comprises an upper optical channel, a lower optical channel, an upper optical channel electrode group, a lower optical channel electrode group, a combination of the upper optical channel and the upper optical channel electrode group, and a combination of the lower optical channel and the lower optical channel electrode group. The purpose of the present invention is to provide a packaged integrated fiber optic gyroscope and a manufacturing method thereof, so as to achieve miniaturization and high precision of the fiber optic gyroscope.

Description

Technical Field

[0001] The present application relates to the technical field of inertial measurement devices, and specifically discloses a packaged integrated fiber optic gyroscope structure and a manufacturing method thereof. Background Art

[0002] A fiber optic gyroscope (FOG) is an inertial sensor based on optical principles used to measure and detect the rotation of an object. It uses the Sagnac effect to measure the object's angular velocity. When a light beam travels over a rotating object, it follows the Sagnac effect. This means that if a light beam propagates in a closed path and that path rotates, the beam will propagate in two directions, creating a phase difference. This phase difference is proportional to the object's angular velocity. FOGs typically use a fiber optic loop to measure angular velocity. The light beam emitted by a light source is split into two parts, propagating in clockwise and counterclockwise directions, respectively, before eventually reuniting to form an interference pattern. When the fiber optic loop rotates, the Sagnac effect causes the optical path difference between the two beams to change, causing the interference pattern to shift. By detecting the movement of the interference pattern, the angular velocity of the fiber optic loop can be measured.

[0003] Fiber optic gyroscopes are widely used in inertial navigation in aerospace, ships, missiles and other fields. They have the advantages of small size, light weight and high detection accuracy. Figure 1 As shown, the optical signal output by the light source (usually a superluminescent diode, SLD) is split into two beams of equal amplitude and non-reciprocal phase when passing through the Y-branch modulator. After entering the optical fiber coil, they are transmitted in the clockwise and counterclockwise directions respectively. After transmitting one circle in the entire optical fiber coil, they return to the Y-branch modulator to combine the beams to form interference. Finally, the interfered optical signal passes through the optical coupler C1 and enters the detector. The interference signal intensity obtained by the detector can be used to detect the Sagnac phase shift, and then the rotation speed of the optical fiber coil can be obtained.

[0004] As the application scope of fiber optic gyroscopes continues to expand, the requirements for their miniaturization and high precision are becoming increasingly stringent. Miniaturization of fiber optic gyroscopes primarily utilizes a combination of integrated circuit technology and advanced packaging techniques, integrating several functions onto the same substrate material or packaging substrate to form an integrated optical module, thereby reducing the structural size of the fiber optic gyroscope. High precision is achieved by employing reentrant structures, digital closed loops, and polarization within the integrated optical module.

[0005] Based on the specification of this application Figure 1Interferometric fiber optic gyroscopes based on the principle of interferometry have a large number of invention patents and utility model patents based on their technical solutions. The implementation plans are mainly divided into two categories: discrete component type and integrated component type. The optical coupler in the discrete component type fiber optic gyroscope can be optical fiber type or an integrated optical waveguide chip manufactured using a planar optical waveguide circuit process; the Y-branch modulator is manufactured using a planar optical waveguide circuit process such as proton exchange. The various components are then interconnected by optical fiber to form the fiber optic gyroscope.

[0006] For example, a common fiber optic gyroscope device and its manufacturing method with Chinese invention patent publication number CN116026309B proposes to discretely distribute the five optical components and circuit boards of the fiber optic gyroscope body in various fragmented spatial positions of the carrier.

[0007] For example, a fiber optic gyroscope with the Chinese invention patent publication number CN115839711B is provided in the appendix of the specification of this application. Figure 1 A second detector is added to the schematic diagram, the Y-branch modulator is changed to a 2×2 modulator, and the components are interconnected by optical fibers.

[0008] For example, the structure of an ultra-high-precision fiber-optic gyroscope (FOG), published in Chinese Invention Patent Publication No. CN113804177B, utilizes a mounting base, a mounting cover, a mounting flange, and an outer housing to form a double-layer magnetic shield. Fiber optic interconnections between the various components of the FOG allow for flexible layout, but the increased number of optical nodes increases coupling losses and reduces overall reliability.

[0009] Integrated component fiber gyros, including hybrid integration and packaged integration, have the advantages of small size, compact structure, and light weight. Hybrid integration refers to the direct coupling or lensing of component chips and assemblies made of different materials and packaging them on the same substrate. For example, the hybrid integrated optical device of PLC chip and lithium niobate modulator with Chinese invention patent publication number CN106092080B integrates a polarization-maintaining single-core optical fiber for the input light source, a Y-shaped beamsplitter chip based on planar light waveguide circuit technology (PLC), a lithium niobate modulator chip, a PLC-based resonant ring chip, and a PIN photodetector on a U-shaped board. For example, the system architecture for an integrated photonic optical gyroscope with Chinese invention patent publication number CN114829876A uses integrated photonic technology to manufacture all components on the same substrate material, such as a silicon substrate. Due to inherent material limitations, it's difficult to integrate the various optical components of a fiber optic gyroscope onto the same substrate. Typically, this approach maximizes the advantages of each material, such as using III-V indium phosphide (InP) for the light source and detector, lithium niobate for the modulator, and silicon dioxide, silicon nitride, or silicon for the coupler and interconnecting optical waveguides. Furthermore, hybrid integrated manufacturing processes are relatively complex and costly.

[0010] Package integration refers to the assembly of some or all components through spatial optical elements such as lenses to form a single assembly. For example, Chinese invention patent application CN116203682A, which describes a miniaturized optical transceiver device and its manufacturing method, provides an optical transceiver module for a fiber optic gyroscope. This module integrates a light source chip, lens, optical coupling chip, and optical detection chip through packaging, and then interconnects them with a Y-branch modulator and optical fiber coil. It also proposes arranging the input and output optical paths of the coupler chip on the same or different sides, and using either a single or dual detector.

[0011] Fiber optic gyroscopes based on packaged integration technology have obvious advantages and are currently the main technology for the development of fiber optic gyroscopes. However, existing packaged integrated fiber optic gyroscope implementation plans cannot take into account both miniaturization and high precision. The present invention provides a miniaturized, high-precision fiber optic gyroscope structure and manufacturing method based on an integrated optical module. Summary of the Invention

[0012] The purpose of the present invention is to provide a packaged integrated fiber optic gyroscope structure and a manufacturing method thereof, which reduces the manufacturing difficulty, improves the production efficiency, and realizes the miniaturization and high precision of the fiber optic gyroscope through modular design and assembly.

[0013] In order to achieve the above object, the present invention provides the following basic scheme:

[0014] A packaged integrated fiber optic gyroscope structure includes a substrate and an optical coupling chip disposed on the substrate, an optical modulation chip, an optical fiber ring connected to the optical modulation chip, a laser function lens assembly connected to the optical coupling chip for emitting laser light, an optical detection chip, and a circuit processing module for realizing normal operation of the fiber optic gyroscope;

[0015] The optical modulation chip adopts a straight-arm modulator, and the optical coupling chip includes a transmission waveguide, a first 3dB coupler connected to the optical modulation chip, and a second 3dB coupler connected to the laser functional mirror group;

[0016] The optical modulation chip includes an upper optical channel, a lower optical channel, an upper optical channel electrode group and a lower optical channel electrode group, a combination of the upper optical channel and the upper optical channel electrode group, and a combination of the lower optical channel and the lower optical channel electrode group.

[0017] Furthermore, the circuit processing module is the circuit processing part of the fiber optic gyroscope, and the circuit processing module includes a driver, a digital logic processing module, a digital output module and a signal output port, and the signal output port connects the circuit processing module with the fiber optic gyroscope signal.

[0018] Furthermore, the first 3dB coupler has a first output port a and a first output port b, the second 3dB coupler has a second output port and a second input port, the first output port a and the first output port b are connected to the input port of the optical modulation chip, the second output port is connected to the optical detection chip, and the second input port is connected to the laser functional mirror group.

[0019] Furthermore, the second output port is connected to a fourth 3dB coupler. The fourth 3dB coupler has the second output port of the second 3dB coupler and adds a third output port. Both the third output port and the second output port are connected to the optical detection chip.

[0020] Furthermore, the material of the optical modulation chip is lithium niobate, and the two ports of the optical fiber ring are respectively a first port and a second port, the first port is connected to the upper optical channel in the optical modulation chip, and the second port is connected to the lower optical channel in the optical modulation chip.

[0021] Furthermore, it also includes a third 3dB coupler and an optical detector connected to the third 3dB coupler for phase monitoring of the upper optical channel and the lower optical channel. A downlink optical splitter is provided on the upper optical channel and the lower optical channel in the optical modulation chip, the downlink optical splitter is connected to the third 3dB coupler, and the optical detector is connected to the circuit processing module.

[0022] Furthermore, the laser functional mirror group includes a laser chip, a first focusing collimating lens group, a second focusing collimating lens group, an optical isolator, a backlight detection chip and a plate base. The second focusing collimating lens group adjusts the light emitted by the laser chip into parallel light. The parallel light passes through the optical isolator and then is coupled to the second input port through the first focusing collimating lens group.

[0023] Furthermore, the laser chip and the backlight detection chip are bonded to the board seat through AuSn solder, and the laser functional lens group and the light detection chip are bonded to the substrate through AuSn solder.

[0024] The basic solution of the present application also provides a method for manufacturing a packaged integrated fiber optic gyroscope structure, which is used to manufacture the packaged integrated fiber optic gyroscope structure as described above, comprising the following steps:

[0025] Step S01: Prepare a substrate, and assemble the laser functional mirror group, optical coupling chip, optical modulation chip and optical detection chip on the same substrate 11;

[0026] Step S02: fixing the plate base on the substrate, and assembling the laser chip, the first focusing collimating lens group, the second focusing collimating lens group, the optical isolator and the backlight detection chip on the plate base;

[0027] Step S03: After step S01 and step S02 are completed, all the above parts are packaged and integrated, coupled and interconnected with the optical fiber ring, and assembled through a modular design to obtain a fiber optic gyroscope.

[0028] The principle and effect of this solution are:

[0029] 1. Compared to the prior art, the present invention aims to provide a packaged, integrated fiber optic gyroscope structure. Taking into account material properties and manufacturing processes, the present invention optimizes the integration scheme to achieve optimal optical and mechanical performance while ensuring miniaturization and high precision. The fiber optic gyroscope structure of the present invention includes a laser chip, a laser functional lens assembly, an optical coupling chip, an optical modulation chip, and a light detection chip. It features high integration, a small size, and low cost, reducing the structural dimensions of the fiber optic gyroscope and lowering its manufacturing difficulty.

[0030] 2. Compared with the prior art, the present invention adds a monitoring coupling structure to the optical modulation chip for phase monitoring, and uses a dual light detector with a common ground at the output end of the optical coupling chip, thereby improving the detection accuracy of the fiber optic gyroscope.

[0031] 3. Compared with the prior art, the purpose of the present invention is to provide a method for manufacturing a packaged integrated fiber optic gyroscope structure. The laser functional mirror group, optical coupling chip, optical modulation chip and optical detection chip are assembled on the same substrate, packaged in a module, and coupled and interconnected with an optical fiber ring. Through modular design and assembly, the manufacturing difficulty is reduced and the production efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A schematic diagram of a fiber optic gyroscope in the prior art is shown;

[0034] Figure 2 A schematic structural diagram of a packaged and integrated fiber optic gyroscope structure proposed in an embodiment of the present application is shown;

[0035] Figure 3 A schematic diagram of the structure of an optical coupling chip in a packaged and integrated fiber optic gyroscope structure proposed in an embodiment of the present application is shown;

[0036] Figure 4 A schematic diagram of the structure of an optical modulation chip in a packaged and integrated fiber optic gyroscope structure proposed in an embodiment of the present application is shown;

[0037] Figure 5 A schematic structural diagram of a laser functional mirror group in a packaged integrated fiber optic gyroscope structure proposed in an embodiment of the present application is shown;

[0038] Figure 6 A schematic diagram showing the position of a signal output port in a packaged integrated fiber optic gyroscope structure proposed in an embodiment of the present application is shown;

[0039] Figure 7 A schematic diagram showing the layout structure of dual light detection chips in a packaged integrated fiber optic gyroscope structure proposed in an embodiment of the present application is shown;

[0040] Figure 8 The structure and principle diagram of phase monitoring in a packaged integrated fiber optic gyroscope structure proposed in an embodiment of the present application are shown. DETAILED DESCRIPTION

[0041] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0042] The figure marks in the drawings of the specification include: fiber optic gyroscope 1, substrate 11, optical coupling chip 2, first 3dB coupler 21, second 3dB coupler 22, transmission waveguide 23, first output port a211, second output port b212, second input port 221, second output port 222, fourth 3dB coupler 223, third output port 224, optical modulation chip 3, upper optical channel 31, lower optical channel 32, upper optical channel electrode group 33, lower optical channel electrode group 34, third 3dB coupler 35, optical fiber ring 4, first port 41, second port 42, circuit processing module 5, laser function mirror group 6, first focusing and collimating lens group 61, optical isolator 62, second focusing and collimating lens group 63, laser chip 64, backlight detection chip 65, board base 67, optical detection chip 7, optical detector 8, signal output port 9.

[0043] Implementation example Figure 2-Figure 8 As shown:

[0044] A packaged integrated fiber optic gyroscope structure, such as Figure 2-Figure 5 As shown, the fiber optic gyroscope 1 is composed of a substrate 11 with good thermal stability, an optical coupling chip 2, an optical modulation chip 3, an optical fiber ring 4, a laser functional lens group 6 and an optical detection chip 7. The circuit processing module 5 is the circuit processing part of the fiber optic gyroscope 1. The substrate 11 requires a material with good thermal stability, specifically indium watt alloy or tungsten copper material. The optical coupling chip 2 and the optical modulation chip 3 are bonded to the substrate 11 by an optical adhesive with small curing shrinkage and good thermal stability. Figure 5 As shown, the laser functional mirror group 6 and the light detection chip 7 are bonded to the substrate 11 through AuSn solder. AuSn solder can achieve good welding on a variety of substrates 11, which helps to maintain the electrical performance and heat dissipation performance of the device. Figure 4 As shown, the two ports of the optical fiber ring 4 are respectively the first port 41 and the second port 42. The first port 41 and the second port 42 are respectively bonded to the two output ports of the optical modulation chip 3 by optical glue with small curing shrinkage and good thermal stability, which is conducive to the subsequent forward movement of the Y branch to the optical coupling chip 2 and reducing the overall optical transmission loss of the optical fiber gyroscope 1.

[0045] like Figure 3As shown, the optical coupling chip 2 consists of a transmission waveguide 23, a first 3dB coupler 21, and a second 3dB coupler 22. To ensure a compact size and a core-cladding refractive index difference of at least 1.5%, the optical coupling chip 2 is constructed from a low-transmission-loss material such as germanium dioxide-doped silicon dioxide or silicon oxynitride. The output ports of the first 3dB coupler 21 in the optical coupling chip 2 are a first output port a211 and a second output port b212, respectively. These ports a211 and b212 are bonded to the input ports of the optical modulation chip 3 using an optical adhesive with low curing shrinkage and good thermal stability.

[0046] The second 3dB coupler 22 has a second output port 222 and a second input port 221. The second input port 221 of the second 3dB coupler 22 of the optical coupling chip 2 is spatially optically coupled to the laser functional lens assembly 6. The second output port 222 of the second 3dB coupler 22 of the optical coupling chip 2 is spatially optically coupled to the optical detection chip 7.

[0047] like Figure 4 As shown, the optical modulation chip 3 is composed of an upper optical channel 31, a lower optical channel 32, an upper optical channel electrode group 33 and a lower optical channel electrode group 34. The upper optical channel 31 is combined with the upper optical channel electrode group 33, and the lower optical channel 32 is combined with the lower optical channel electrode group 34. Figure 4 As shown, the conventional Y-branch modulator is replaced with a straight-arm modulator, which reduces the transmission loss caused by the Y-branch. The optical modulation chip 3 is made of lithium niobate, which achieves high modulation efficiency through a proton exchange process, but also suffers from high optical transmission loss. Therefore, the present invention moves the Y-branch forward onto the optical coupling chip 2, reducing the overall optical transmission loss of the fiber optic gyroscope 1.

[0048] like Figure 4 As shown, the two ports of the optical fiber ring 4 are respectively the first port 41 and the second port 42. The optical fiber ring 4 is formed by winding a polarization-maintaining optical fiber. The first port 41 and the second port 42 are bonded together with the upper optical channel 31 and the lower optical channel 32 in the optical modulation chip 3 by an optical adhesive with small curing shrinkage and good thermal stability. The upper optical channel electrode group 33 and the lower optical channel electrode group 34 are connected to the first output port a211 and the second output port b212.

[0049] like Figure 5 As shown, the laser functional lens group 6 is composed of a laser chip 64 , a first focusing and collimating lens group 61 , a second focusing and collimating lens group 63 , an optical isolator 62 , a backlight detection chip 65 and a plate base 67 .

[0050] The second focusing and collimating lens group 63 collimates the light emitted by the laser chip 64 into parallel light, which is then coupled through the optical isolator 62 and then through the first focusing and collimating lens group 61 to the second input port 221 of the second 3dB coupler 22 of the optical coupling chip 2. The optical isolator 62 prevents light returning from the fiber ring 4 from passing through the first 3dB coupler 21 of the optical coupling chip 2 and then retracing its original path to the laser function lens group 6, potentially damaging the laser chip 64. The laser chip 64 and the backlight detection chip 65 are bonded to the board base 67 using AuSn solder. The first and second focusing and collimating lens groups 61, 63, and the optical isolator 62 are bonded to the board base 67 using an optical adhesive with low curing shrinkage and good thermal stability. The positions of the laser chip 64, the first and second focusing and collimating lens groups 61, 63, the optical isolator 62, and the backlight detection chip 65 must be carefully adjusted and aligned to achieve maximum coupling efficiency. The plate base 67 is made of a material having excellent thermal stability, such as AlN or glass ceramic.

[0051] like Figure 6 As shown, the circuit processing module 5 is the circuit processing part of the fiber optic gyroscope 1, and is specifically as follows:

[0052] The circuit processing module 5 includes a driver, a digital logic processing module, a digital output module, and a signal output port 9. The signal output port 9 connects the circuit processing module 5 to the fiber optic gyroscope 1 signal. The circuit processing module 5 mainly provides a driver for the laser chip 64, provides a photocurrent signal amplification for the light detection chip 7 and the backlight detection chip 65, provides a driver for the light modulation chip 3, and coordinates the laser chip 64, the light detection chip 7, the backlight detection chip 65, and the light modulation chip 3 to achieve normal operation of the fiber optic gyroscope 1.

[0053] like Figure 7 and Figure 8 As shown, in order to improve the detection accuracy of the fiber optic gyroscope 1, this solution also provides two solutions to further improve the detection accuracy of the fiber optic gyroscope 1:

[0054] like Figure 8 As shown, Solution 1 is to add a 1% to 5% power downlink optical splitter to the upper optical channel 31 and the lower optical channel 32 of the optical modulation chip 3. The 1% to 5% power downlink optical splitter means that the optical splitter can distribute the power of the input optical signal to each output port according to a certain proportion (1% to 5%). Then, a third 3dB coupler 35 is added. Then, the signal enters the optical detector 8 through the third 3dB coupler 35 to realize phase monitoring of the upper optical channel 31 and the lower optical channel 32 of the optical modulation chip 3. The optical detector 8 is interconnected with the circuit processing module 5 of the fiber optic gyroscope 1 for processing.

[0055] Further explanation of the principle of phase monitoring:

[0056] The light from the upper optical channel 31 and the lower optical channel 32 has a phase difference, which generates interference radiation when entering the third 3dB coupler 35. The phase difference can be detected by the photodetector 8. This phase difference is sent to the circuit processing module 5 as a closed-loop control signal, which can improve the accuracy of the fiber optic gyroscope.

[0057] like Figure 7 As shown, Solution 2 is to add a fourth 3dB coupler 223 before the second output port 222 of the second 3dB coupler 22 of the optical coupling chip 2. The fourth 3dB coupler 223 has not only the second output port 222 but also the third output port 224. The single optical detection chip 7 of the original solution can be replaced with a dual optical detection chip 7 with a common ground to improve detection accuracy.

[0058] Solution 1 and Solution 2 can be applied individually or together, and both can improve the detection accuracy of the fiber optic gyroscope 1 without increasing the structural size of the fiber optic gyroscope 1.

[0059] The optical adhesives with small curing shrinkage and good thermal stability at different positions mentioned above are all the same, specifically model at3826p, with a shrinkage rate of less than 0.5% and a thermal expansion coefficient of less than 40ppm / ℃.

[0060] The advantages of this solution are:

[0061] 1. Ensure the miniaturization and high precision of the fiber optic gyroscope 1, including the laser chip 64, the laser functional mirror group 6, the optical coupling chip 2, the optical modulation chip 3 and the optical detection chip 7.

[0062] 2. The first 3dB coupler 21 and the second 3dB coupler 22 are used to move the Y-branch structure of the optical modulation chip 3 forward into the optical coupling chip 2 , thereby reducing the overall optical transmission loss of the optical fiber gyroscope 1 .

[0063] 3. Add monitoring coupling structures to the upper optical channel 31 and the lower optical channel 32 of the optical modulation chip 3, and combine the beams into the optical detector 8 for phase monitoring.

[0064] 4. A fourth 3dB coupler 223 is added before the output of the optical coupling chip 2 is sent to the optical detection chip 7, and then the optical detection chip 7 with a common ground is input.

[0065] The basic solution of the present application also provides a method for manufacturing a packaged integrated fiber optic gyroscope 1 structure, comprising the following steps:

[0066] S01: Prepare a substrate 11, and assemble the laser functional lens group 6, the optical coupling chip 2, the optical modulation chip 3 and the optical detection chip 7 on the same substrate 11;

[0067] S02: Fix the plate base 67 on the substrate 11, and assemble the laser chip 64, the first focusing and collimating lens group 61, the second focusing and collimating lens group 63, the optical isolator 62 and the backlight detection chip 65 on the plate base 67;

[0068] S03: After step S01 and step S02 are completed, all the above components are packaged and integrated, coupled and interconnected with the optical fiber ring 4, and assembled through a modular design to obtain the optical fiber gyroscope 1.

[0069] The present invention aims to provide a packaged integrated fiber optic gyroscope structure and a manufacturing method thereof, which reduces manufacturing difficulty and improves production efficiency through modular design and assembly, thereby achieving miniaturization and high precision of the fiber optic gyroscope.

[0070] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A packaged integrated fiber optic gyroscope structure, characterized in that: The optical fiber gyroscope comprises a substrate and an optical coupling chip, an optical modulation chip, an optical fiber ring connected to the optical modulation chip, a laser function lens group connected to the optical coupling chip for emitting laser light, an optical detection chip, and a circuit processing module for realizing normal operation of the optical fiber gyroscope. The optical modulation chip adopts a straight-arm modulator, and the optical coupling chip includes a transmission waveguide, a first 3dB coupler connected to the optical modulation chip, and a second 3dB coupler connected to the laser functional mirror group; The optical modulation chip includes an upper optical channel, a lower optical channel, an upper optical channel electrode group and a lower optical channel electrode group, a combination of the upper optical channel and the upper optical channel electrode group, and a combination of the lower optical channel and the lower optical channel electrode group; It also includes a third 3dB coupler and an optical detector connected to the third 3dB coupler for phase monitoring of the upper optical channel and the lower optical channel. A downlink optical splitter is provided on the upper optical channel and the lower optical channel in the optical modulation chip. The downlink optical splitter is connected to the third 3dB coupler, and the optical detector is connected to the circuit processing module.

2. The packaged integrated fiber optic gyroscope structure according to claim 1, characterized in that: The circuit processing module is the circuit processing part of the fiber optic gyroscope. The circuit processing module includes a driver, a digital logic processing module, a digital output module and a signal output port. The signal output port connects the circuit processing module with the fiber optic gyroscope signal.

3. The packaged integrated fiber optic gyroscope structure according to claim 2, characterized in that: The first 3dB coupler has a first output port a and a first output port b, and the second 3dB coupler has a second output port and a second input port. The first output port a and the first output port b are connected to the input port of the optical modulation chip, the second output port is connected to the optical detection chip, and the second input port is connected to the laser functional mirror group.

4. The packaged integrated fiber optic gyroscope structure according to claim 3, characterized in that: The second output port is connected to a fourth 3dB coupler. The fourth 3dB coupler includes the second output port of the second 3dB coupler and a third output port. Both the third output port and the second output port are connected to the optical detection chip.

5. The packaged integrated fiber optic gyroscope structure according to claim 3 or 4, characterized in that: The optical modulation chip is made of lithium niobate. The two ports of the optical fiber ring are respectively a first port and a second port. The first port is connected to the upper optical channel in the optical modulation chip, and the second port is connected to the lower optical channel in the optical modulation chip.

6. The packaged integrated fiber optic gyroscope structure according to claim 5, characterized in that: The laser functional mirror group includes a laser chip, a first focusing collimating lens group, a second focusing collimating lens group, an optical isolator, a backlight detection chip and a plate base. The second focusing collimating lens group adjusts the light emitted by the laser chip into parallel light. The parallel light passes through the optical isolator and then couples to the second input port through the first focusing collimating lens group.

7. The packaged integrated fiber optic gyroscope structure according to claim 6, characterized in that: The laser chip and the backlight detection chip are bonded to the board seat through AuSn solder, and the laser functional lens group and the light detection chip are bonded to the substrate through AuSn solder.

8. A method for manufacturing a packaged integrated fiber optic gyroscope structure, for manufacturing the packaged integrated fiber optic gyroscope structure according to claim 7, characterized in that: The following steps are involved: Step S01: preparing a substrate, and assembling a laser functional mirror group, an optical coupling chip, an optical modulation chip, and an optical detection chip on the same substrate; Step S02: fixing the plate base on the substrate, and assembling the laser chip, the first focusing and collimating lens group, the second focusing and collimating lens group, the optical isolator and the backlight detection chip on the plate base; Step S03: After step S01 and step S02 are completed, all the above parts are packaged and integrated, coupled and interconnected with the optical fiber ring, and assembled through a modular design to obtain a fiber optic gyroscope.

Images