Encapsulated and integrated optical fiber gyroscope structure and manufacturing method thereof

Abstract

The invention relates to the technical field of inertial measurement devices, and particularly discloses a packaged and integrated optical fiber gyroscope structure and a manufacturing method thereof. Comprising a substrate, and an optical coupling chip, an optical modulation chip, an optical fiber ring connected with the optical modulation chip, a laser function lens group connected with the optical coupling chip and used for emitting laser, an optical detection chip and a circuit processing module for realizing normal work of the optical fiber gyroscope, which are arranged on the substrate, the optical coupling chip adopts a straight arm modulator and comprises a transmission waveguide, a first 3dB coupler connected with the optical modulation chip and a second 3dB coupler connected with the laser functional lens 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. And miniaturization and high precision of the optical fiber gyroscope are realized.

Description

Technical Field

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

[0002] A fiber optic gyroscope (FOG) is an inertial sensor based on the optical principle, used to measure and detect the rotation of an object. The fiber optic gyroscope utilizes the Sagnac effect to measure the rotational angular velocity of an object. When a light beam travels on a rotating object, it follows the Sagnac effect, that is, when the light beam propagates in a closed path, if the path rotates, the light beam will propagate in two directions respectively, forming a phase difference. This phase difference is proportional to the rotational angular velocity of the object. The fiber optic gyroscope usually uses a fiber optic loop to measure the rotational angular velocity. The light signal emitted by the light source is split into two parts, which propagate along the clockwise and counterclockwise directions respectively, and finally converge again to form an interference pattern. When the fiber optic loop rotates, due to the Sagnac effect, the optical path difference between the two light beams changes, resulting in the movement of the interference pattern. By detecting the movement of the interference pattern, the rotational angular velocity of the fiber optic loop can be measured.

[0003] Fiber optic gyroscopes are widely used in inertial navigation in the fields of aerospace, ships, missiles, etc., and have the advantages of small size, light weight, high detection accuracy, etc. The principle is as shown in the attached drawings of the specification of this application. Figure 1 When the optical signal output by the light source (usually a superluminescent light emitting diode, SLD) passes through the Y-branch modulator, it is split into two optical signal beams with equal amplitude and non-reciprocal phases. After entering the fiber optic coil, they are transmitted along the clockwise and counterclockwise directions respectively. After traveling one circle in the entire fiber optic coil, they return to the Y-branch modulator for beam combination to form interference. Finally, the interfered optical signal passes through the optical coupler C1 and enters the detector. The rotational speed of the fiber optic coil can be obtained by sensing the Sagnac phase shift through the interference signal intensity obtained by the detector.

[0004] With the continuous expansion of the application scope of fiber optic gyroscopes, the requirements for their miniaturization and high precision are getting higher and higher. The miniaturization of fiber optic gyroscopes mainly combines integrated circuit technology and advanced packaging technology to integrate some functions on the same substrate material or packaging substrate to form an integrated optical module, so as to reduce the structural size of the fiber optic gyroscope; high precision is achieved by adopting re-entrant structures, digital closed loops, polarization, etc. in the integrated optical module.

[0005] Based on the attached drawings of the specification of this application Figure 1For the principle of interferometric fiber optic gyroscopes, there are many invention patents and utility model patents applied based on their technical solutions. There are mainly two categories of implementation schemes, namely discrete component type and integrated component type. The optical coupler in the discrete component type fiber optic gyroscope can be of the fiber type or an integrated optical waveguide chip manufactured using planar optical waveguide loop technology; the Y-branch modulator is manufactured using planar optical waveguide loop technologies such as proton exchange, and then each component is interconnected through optical fibers to form a fiber optic gyroscope.

[0006] For example, a co-form fiber optic gyroscope device and its manufacturing method with the Chinese invention patent publication number CN116026309B proposes to discretely distribute the five major optical devices and circuit board 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 adds a second detector to the schematic diagram of this application, changes the Y-branch modulator to a 2×2 modulator, and interconnects each component through optical fibers. Figure 1

[0008] For example, a structure of an ultra-high-precision fiber optic gyroscope with the Chinese invention patent publication number CN113804177B adopts a double-layer magnetic shielding design formed by an installation base, an installation upper cover, an installation flange, and an outer cover, and interconnects each component through optical fibers. Each component of the fiber optic gyroscope is interconnected through optical fibers, and its structure can be arranged as needed, which is relatively flexible, but it increases the optical connection nodes, increases the coupling loss, and its overall reliability also decreases accordingly.

[0009] ​Integrated component type fiber optic gyroscopes include hybrid integration and package integration, and have the advantages of small size, compact structure and light weight. Hybrid integration means directly or through lenses coupling and packaging component chips and components made of different materials on the same substrate. For example, the PLC chip and lithium niobate modulator hybrid integrated optical device with the Chinese invention patent publication number CN106092080B integrates a polarization maintaining single-core fiber for the input light source, a Y-branch splitter chip based on the planar lightwave circuit process (PLC), a lithium niobate modulator chip, a resonant ring chip based on PLC and a PIN photodetector on a U-shaped board; Another example is the system architecture for an integrated photonics optical gyroscope with the Chinese invention patent application publication number CN114829876A, which manufactures all components on the same substrate material using the integrated photonics process, such as a silicon material substrate. Due to the limitations of the materials themselves, it is difficult to integrally manufacture the optical components of fiber optic gyroscopes on the same substrate material. Usually, the advantages of each material are maximized. For example, III-V group indium phosphide (InP) material is used to manufacture light sources and detectors, lithium niobate material is used to manufacture modulators, and silica, silicon nitride or silicon material is used to manufacture couplers and interconnecting optical waveguides. And the hybrid integration manufacturing process is relatively complex and costly.

[0010] Package integration means assembling some or all components together through spatial optical components such as lenses to form a component. For example, a miniaturized optical transceiver device and its manufacturing method with the Chinese invention patent application publication number CN116203682A provides an optical transceiver module for a fiber optic gyroscope, which integrates a light source chip, a lens, an optical coupling chip and an optical detection chip through package integration to form an optical transceiver module, and then interconnects it with a Y-branch modulator and a fiber coil. At the same time, it is also proposed to arrange the input and output optical paths of the coupler chip on the same side or different sides; single detectors or double detectors are used for the detectors.

[0011] The fiber optic gyroscope based on package integration technology has obvious advantages and is the main technology for the development of fiber optic gyroscopes at present. However, the existing implementation schemes of package integrated fiber optic gyroscopes cannot take into account both miniaturization and high precision. The present invention provides a miniaturized and 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 package integrated fiber optic gyroscope structure and its manufacturing method. Through modular design and assembly, the manufacturing difficulty is reduced, the production efficiency is improved, and the miniaturization and high precision of the fiber optic gyroscope are achieved.

[0013] To achieve the above object, the present invention provides the following basic solution: An encapsulated and integrated fiber optic gyroscope structure includes a substrate, an optical coupling chip, an optical modulation chip, a fiber optic loop connected to the optical modulation chip, a laser function mirror group for emitting laser light connected to the optical coupling chip, an optical detection chip, and a circuit processing module for enabling the normal operation of the fiber optic gyroscope; The optical coupling chip uses a straight-arm modulator. 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 function 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. The upper optical channel and the upper optical channel electrode group are combined, and the lower optical channel and the lower optical channel electrode group are combined.

[0014] Furthermore, 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 to the fiber optic gyroscope signal.

[0015] 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 function mirror group.

[0016] Furthermore, the second output port is connected to a fourth 3dB coupler. The fourth 3dB coupler has the second output port in the second 3dB coupler and a new third output port. Both the third output port and the second output port are connected to the optical detection chip.

[0017] Furthermore, the material of the optical modulation chip is lithium niobate. The two ports of the fiber optic loop 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.

[0018] Furthermore, it also includes a third 3dB coupler and an optical detector connected to the third 3dB coupler for monitoring the phases of the upper optical channel and the lower optical channel. A downward splitter is provided on the upper optical channel and the lower optical channel in the optical modulation chip. The downward splitter is connected to the third 3dB coupler, and the optical detector is connected to the circuit processing module.

[0019] Furthermore, the laser function mirror group includes a laser chip, a first focusing and collimating lens group, a second focusing and collimating lens group, an optical isolator, a backlight detection chip, and a board seat. The second focusing and 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 and collimating lens group.

[0020] Furthermore, the laser chip and the backlight detection chip are bonded to the board base through AuSn solder, and the laser functional mirror group and the optical detection chip are bonded to the substrate through AuSn solder.

[0021] The basic solution of this application also provides a manufacturing method for a packaged and integrated fiber optic gyroscope structure for manufacturing a packaged and integrated fiber optic gyroscope structure as described above, including the following steps: Step S01: Prepare a substrate, and assemble a laser functional mirror group, an optical coupling chip, an optical modulation chip, and an optical detection chip on the same substrate 11; Step S02: Fix the board base on the base, and assemble a laser chip, a first focusing and collimating lens group, a second focusing and collimating lens group, an optical isolator, and a backlight detection chip on the board base; Step S03: After Steps S01 and S02 are completed, package and integrate all the above parts, couple and interconnect them with the fiber optic ring, and assemble them through modular design to obtain a fiber optic gyroscope.

[0022] The principle and effect of this solution are as follows: 1. Compared with the prior art, the purpose of the present invention is to provide a packaged and integrated fiber optic gyroscope structure. By comprehensively considering material characteristics and manufacturing processes, an optimal integration solution is selected to achieve the best optical and mechanical properties, while ensuring miniaturization and high precision. The fiber optic gyroscope structure of the present invention includes a laser chip, a laser functional mirror group, an optical coupling chip, an optical modulation chip, and an optical detection chip, and has the characteristics of high integration, small size, and low cost, reducing the structural size of the fiber optic gyroscope and the manufacturing difficulty.

[0023] 2. Compared with the prior art, the present invention adds a monitoring coupling structure on the optical modulation chip for phase monitoring, and the output end of the optical coupling chip uses a common-ground dual photodetector, improving the detection accuracy of the fiber optic gyroscope.

[0024] 3. Compared with the prior art, the purpose of the present invention is to provide a manufacturing method for a packaged and integrated fiber optic gyroscope structure. The laser functional mirror group, the optical coupling chip, the optical modulation chip, and the optical detection chip are assembled on the same substrate, packaged in a module, and coupled and interconnected with the fiber optic ring. Through modular design and assembly, the manufacturing difficulty is reduced and the production efficiency is improved. Description of the Drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 Shows a schematic diagram of a fiber optic gyroscope in the prior art; Figure 2 Shows a schematic structural diagram of an encapsulated and integrated fiber optic gyroscope structure proposed in an embodiment of the present application; Figure 3 Shows a schematic structural diagram of an optical coupling chip in an encapsulated and integrated fiber optic gyroscope structure proposed in an embodiment of the present application; Figure 4 Shows a schematic structural diagram of an optical modulation chip in an encapsulated and integrated fiber optic gyroscope structure proposed in an embodiment of the present application; Figure 5 Shows a schematic structural diagram of a laser functional mirror group in an encapsulated and integrated fiber optic gyroscope structure proposed in an embodiment of the present application; Figure 6 Shows a schematic diagram of the position of a signal output port in an encapsulated and integrated fiber optic gyroscope structure proposed in an embodiment of the present application; Figure 7 Shows a schematic layout structure diagram of a dual optical detection chip in an encapsulated and integrated fiber optic gyroscope structure proposed in an embodiment of the present application; Figure 8 Shows a schematic diagram of the structure and principle of phase monitoring in an encapsulated and integrated fiber optic gyroscope structure proposed in an embodiment of the present application. Detailed implementation manners

[0027] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features, and their effects according to the present invention as follows.

[0028] The reference numerals in the accompanying 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 loop 4, first port 41, second port 42, circuit processing module 5, laser function mirror group 6, first focusing collimating lens group 61, optical isolator 62, second focusing collimating lens group 63, laser chip 64, backlight detection chip 65, board seat 67, optical detection chip 7, photodetector 8, signal output port 9.

[0029] For example, Figures 2 - 8 as shown: A packaged and integrated fiber optic gyroscope structure, as Figures 2 - 5 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 loop 4, a laser function mirror 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 invar alloy or tungsten copper material. The optical coupling chip 2 and the optical modulation chip 3 are bonded to the substrate 11 with an optical adhesive that has small curing shrinkage and good thermal stability, as Figure 5 shown, the laser function mirror group 6 and the optical detection chip 7 are bonded to the substrate 11 through AuSn solder. AuSn solder can achieve good welding on various substrates 11, which helps to maintain the electrical performance and heat dissipation performance of the device, as Figure 4 shown, the two ports of the optical fiber loop 4 are the first port 41 and the second port 42 respectively. The first port 41 and the second port 42 are respectively bonded to the two output ports of the optical modulation chip 3 with an optical adhesive that has small curing shrinkage and good thermal stability, which is beneficial to moving the Y-branch forward to the optical coupling chip 2 subsequently and reducing the overall optical transmission loss of the fiber optic gyroscope 1.

[0030] As Figure 3 shown, the optical coupling chip 2 is composed of a transmission waveguide 23, a first 3dB coupler 21, and a second 3dB coupler 22. To ensure that the optical coupling chip 2 has a small size and a core-cladding refractive index difference of not less than 1.5%, the material of the optical coupling chip 2 is a low-loss material such as germanium-doped silica or silicon oxynitride. The output ports of the first 3dB coupler 21 in the optical coupling chip 2 are the first output port a211 and the second output port b212 respectively. The first output port a211 and the second output port b212 are respectively bonded to the input ports of the optical modulation chip 3 with an optical adhesive that has small curing shrinkage and good thermal stability.

[0031] 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 coupled to the laser function mirror group 6 in a form of free space optics. The second output port 222 of the second 3dB coupler 22 of the optical coupling chip 2 is coupled to the optical detection chip 7 in a form of free space optics.

[0032] As Figure 4 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 and the upper optical channel electrode group 33 are combined, and the lower optical channel 32 and the lower optical channel electrode group 34 are combined. As Figure 4 shown, the common Y-branch modulator is changed to a straight-arm modulator, and the straight-arm modulator reduces the transmission loss caused by the Y-branch. The material for manufacturing the optical modulation chip 3 is lithium niobate material, and a relatively high modulation efficiency can be achieved through the proton exchange process, but its optical transmission loss is large. Therefore, in the present invention, the Y-branch is moved forward to the optical coupling chip 2 to reduce the overall optical transmission loss of the fiber optic gyroscope 1.

[0033] As Figure 4 shown, the two ports of the fiber optic loop 4 are a first port 41 and a second port 42 respectively. The fiber optic loop 4 is formed by winding polarization-maintaining fiber. The first port 41 and the second port 42 are bonded to the upper optical channel 31 and the lower optical channel 32 in the optical modulation chip 3 by an optical adhesive with low curing shrinkage and good thermal stability. The upper optical channel electrode group 33 and the lower optical channel electrode group 34 are connected to a first output port a211 and a second output port b212.

[0034] As Figure 5 shown, the laser function mirror 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 board seat 67.

[0035] The second focusing collimating lens group 63 adjusts the light emitted by the laser chip 64 into parallel light, and then couples it through the optical isolator 62 and the first focusing collimating lens group 61 to the second input port 221 of the second 3dB coupler 22 of the optical coupling chip 2. The function of setting the optical isolator 62 is to prevent the light returning from the optical fiber loop 4 from passing through the first 3dB coupler 21 of the optical coupling chip 2, and then entering the laser functional lens group 6 along the original path through the first 3dB coupler 21 of the optical coupling chip 2, causing damage to the laser chip 64. The laser chip 64 and the backlight detection chip 65 are bonded to the board base 67 through AuSn solder. The first focusing collimating lens group 61, the second focusing collimating lens group 63, and the optical isolator 62 are bonded to the board base 67 through an optical adhesive with low curing shrinkage and good thermal stability. The positions of the laser chip 64, the first focusing collimating lens group 61, the second focusing collimating lens group 63, the optical isolator 62, and the backlight detection chip 65 need to be strictly adjusted and aligned to achieve the maximum coupling efficiency. The board base 67 uses materials with excellent thermal stability such as AlN and glass ceramics.

[0036] As Figure 6 shown, the circuit processing module 5 is the circuit processing part of the fiber optic gyroscope 1, specifically as follows: The circuit processing module 5 includes a driving, digital logic processing module, a digital output module, and a signal output port 9. The signal output port 9 signals connect the circuit processing module 5 with the fiber optic gyroscope 1. The circuit processing module 5 mainly provides driving for the laser chip 64, provides optical current signal amplification for the optical detection chip 7 and the backlight detection chip 65, provides driving for the optical modulation chip 3, and coordinates the operation of the laser chip 64, the optical detection chip 7, the backlight detection chip 65, and the optical modulation chip 3 to enable the normal operation of the fiber optic gyroscope 1; As Figure 7 and Figure 8 shown, in order to improve the detection accuracy of the fiber optic gyroscope 1, this solution also provides two more solutions to improve the detection accuracy of the fiber optic gyroscope 1: As Figure 8 shown, Solution 1 is to add a 1% - 5% power down-splitter to the upper optical channel 31 and the lower optical channel 32 of the optical modulation chip 3. The 1% - 5% power down-splitter means that this splitter can distribute the power of the input optical signal according to a certain ratio (1% - 5%) to each output port, and then add a third 3dB coupler 35, and then enter the optical detector 8 through the third 3dB coupler 35 to achieve 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 and is processed.

[0037] Further elaboration on the principle of phase monitoring: There is a phase difference between the light split from the upper optical channel 31 and the lower optical channel 32. The light enters the third 3dB coupler 35 to generate interference, and the phase difference can be detected by the optical detector 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.

[0038] As Figure 7 shown, in Solution 2, a fourth 3dB coupler 223 is added in front of the second output port 222 of the second 3dB coupler 22 of the optical coupling chip 2. The fourth 3dB coupler 223 not only has the second output port 222, but also has a third output port 224. The single optical detection chip 7 in the original solution can be replaced with a co-grounded dual optical detection chip 7 to improve the detection accuracy.

[0039] Solution 1 and Solution 2 can be applied separately or jointly, and both can improve the detection accuracy of the fiber optic gyroscope 1 without increasing the structural size of the fiber optic gyroscope 1.

[0040] The optical adhesives with small curing shrinkage and good thermal stability at different positions described above are the same. The specific model is at3826p, with a shrinkage rate lower than 0.5% and a thermal expansion coefficient lower than 40 ppm / °C.

[0041] The advantages of this solution are as follows: 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.

[0042] 2. Adopt the first 3dB coupler 21 and the second 3dB coupler 22 to move the Y-branch structure of the optical modulation chip 3 forward into the optical coupling chip 2, reducing the overall optical transmission loss of the fiber optic gyroscope 1.

[0043] 3. Add a monitoring coupling structure on the upper optical channel 31 and the lower optical channel 32 of the optical modulation chip 3, and the combined beam enters the optical detector 8 for phase monitoring.

[0044] 4. Add a fourth 3dB coupler 223 before the output of the optical coupling chip 2 to the optical detection chip 7, and enter the co-grounded dual optical detection chip 7.

[0045] The basic solution of this application also provides a manufacturing method for the structure of the packaged and integrated fiber optic gyroscope 1, including the following steps: S01: Prepare the substrate 11, and assemble the laser functional mirror group 6, the optical coupling chip 2, the optical modulation chip 3, and the optical detection chip 7 on the same substrate 11; S02: Fix the board seat 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 board seat 67; S03: After steps S01 and S02 are completed, all the above parts are encapsulated and integrated, and are coupled and interconnected with the optical fiber loop 4, and assembled through modular design to obtain the fiber optic gyroscope 1.

[0046] The object of the present invention is to provide a structure of an encapsulated and integrated fiber optic gyroscope and a manufacturing method thereof. Through modular design and assembly, the manufacturing difficulty is reduced and the production efficiency is improved. The miniaturization and high precision of the fiber optic gyroscope are achieved.

[0047] The above is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An encapsulated and integrated fiber optic gyroscope structure, characterized in that, It includes a substrate, an optical coupling chip, an optical modulation chip, an optical fiber loop connected to the optical modulation chip, a laser functional mirror group connected to the optical coupling chip for emitting laser, an optical detection chip, and a circuit processing module for enabling the normal operation of the fiber optic gyroscope; The optical coupling chip adopts a straight-arm modulator. 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. The upper optical channel and the upper optical channel electrode group are combined, and the lower optical channel and the lower optical channel electrode group are combined.

2. The structure of an encapsulated and integrated fiber optic gyroscope according to claim 1, wherein 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 to the fiber optic gyroscope in a signal connection.

3. The structure of an encapsulated and integrated fiber optic gyroscope according to claim 2, characterized in that, 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.

4. A packaged and 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 has the second output port in the second 3dB coupler and a new third output port. Both the third output port and the second output port are connected to the optical detection chip.

5. A packaged and integrated fiber optic gyroscope structure according to claim 3 or 4, characterized in that The material of the optical modulation chip is lithium niobate. The two ports of the optical fiber loop 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 structure of an encapsulated integrated fiber optic gyroscope according to claim 5, characterized in that, It further 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 splitter is provided on the upper optical channel and the lower optical channel in the optical modulation chip. The downlink splitter is connected to the third 3dB coupler, and the optical detector is connected to the circuit processing module.

7. An integrated packaged fiber optic gyroscope structure according to claim 6, characterized in that, The laser functional mirror group includes a laser chip, a first focusing and collimating lens group, a second focusing and collimating lens group, an optical isolator, a backlight detection chip, and a board seat. The second focusing and 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 and collimating lens group.

8. The structure of an encapsulated and integrated fiber optic gyroscope according to claim 7, characterized in that, The laser chip and the backlight detection chip are bonded to the board seat through AuSn solder. The laser functional mirror group and the optical detection chip are bonded to the substrate through AuSn solder.

9. A manufacturing method of a packaged integrated fiber optic gyroscope structure for manufacturing a packaged integrated fiber optic gyroscope structure as claimed in claim 8, characterized in that, It includes the following steps: Step S01: Prepare a substrate and assemble the laser functional mirror group, the optical coupling chip, the optical modulation chip, and the optical detection chip on the same substrate; Step S02: Fix the board seat on the base and assemble 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 board seat; Step S03: After steps S01 and S02 are completed, encapsulate and integrate all the above parts, couple and interconnect them with the fiber optic loop, and assemble them through modular design to obtain a fiber optic gyroscope.

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