An aging method and aging device for silicon optical gyroscopes

Abstract

This invention relates to the field of silicon photonic gyroscope fabrication and discloses an aging method and apparatus for silicon photonic gyroscopes, comprising four stages: The first stage involves heating the gyroscope to 65±2℃ at a preset heating rate in a static, unpowered state and storing it at a constant temperature for a first preset duration; the second stage involves subjecting the silicon photonic gyroscope to multiple complete high-low temperature cycles in a static, unpowered state; the third stage involves placing the silicon photonic gyroscope in a constant temperature environment of 55±2℃, applying a rated operating voltage for continuous full-power aging, and collecting zero-bias output data of the silicon photonic gyroscope at preset time intervals for performance monitoring; the fourth stage involves heating the gyroscope to 45±2℃ at a heating rate of 0.3-0.8℃ / min in a static, unpowered state and storing it at a constant temperature for a second preset duration. Compared with existing technologies, this method achieves synchronous stabilization of the stress state of the two components and long-term stability of the electrical characteristics of the active device, improving the performance consistency of batch products by more than 52%.

Description

Technical Field

[0001] This invention relates to the field of silicon photonic gyroscope manufacturing, specifically to an aging method and apparatus for silicon photonic gyroscopes. Background Technology

[0002] Silicon Optical Gyroscopes (SOGs) are a new generation of high-precision angular rate sensors developed based on the Sagnac effect and combining silicon-based photonic integration technology with fiber optic gyroscope technology. This gyroscope combines the high precision, shock resistance, and long lifespan advantages of fiber optic gyroscopes with the small size, light weight, high integration, and mass production capabilities of silicon-based photonic integration technology, making it a promising candidate for applications in aerospace, military guidance, autonomous driving, and precision instruments.

[0003] The core structure of a silicon photonic gyroscope consists of two main components: a silicon photonic chip assembly and a polarization-maintaining fiber ring assembly. Their characteristics directly determine the long-term performance stability of the gyroscope.

[0004] (1) The silicon photonic chip assembly is the core of the optical transceiver and signal processing of the silicon photonic gyroscope. It integrates a broadband light source, an electro-optic modulator, a Y-type beam splitter, a polarization controller, and a photodetector on a single chip. The core characteristics of this assembly are: the silicon-based material has a large thermo-optic coefficient, and there is significant residual stress in the waveguide structure, chip bonding interface, and packaging shell; the electrical characteristics of active devices (modulator, detector, light source) are prone to drift with time and environmental stress; the polarization-dependent loss of the waveguide and the fiber-chip coupling efficiency are prone to long-term degradation due to stress release. The above characteristics are one of the core causes of gyroscope zero-bias drift and scaling factor nonlinear degradation.

[0005] (2) The fiber optic ring assembly is the angular rate sensing core of the silicon photonic gyroscope, which realizes rotation sensing based on the Sagnac effect. The core characteristics of this assembly are that its performance is greatly affected by the birefringence stability of the fiber, the residual stress of the ring winding, the internal stress of the cured adhesive, and the stress relaxation of the coating layer. Uneven or insufficient stress release will directly cause the zero bias of the gyroscope to drift irreversibly with temperature and time, and its optimal stress release conditions are significantly different from those of silicon photonic chips.

[0006] Currently, all aging treatment technologies for silicon photonic gyroscopes suffer from significant compatibility issues. For example:

[0007] 1. Traditional fiber optic gyroscope aging schemes. These schemes typically employ a single-step high-temperature storage aging process, with typical parameters including 168 hours of constant temperature storage at 85°C without power. Their core focus is on the coupling stability of discrete optical components and stress release from the fiber optic ring. However, this scheme is completely unsuitable for the integrated characteristics of silicon photonic chips: excessively high temperatures can exacerbate thermal mismatch at the silicon chip bonding interface, aging of modulator electrodes, and irreversible degradation of waveguide polarization characteristics; while excessively low temperatures cannot adequately release the residual stress in the fiber optic ring. Therefore, this scheme cannot simultaneously address the differentiated aging requirements of the two core components—the silicon photonic chip and the polarization-maintaining fiber optic ring—resulting in extremely poor long-term stability improvements for silicon photonic gyroscopes.

[0008] 2. CN115638781B discloses an online aging method and apparatus for fiber optic rings of a high-precision fiber optic gyroscope. This method involves coaxially mounting a wound fiber optic ring with uncured adhesive onto a rotating shaft of a sealed aging chamber. An external parameter acquisition unit, including a fiber optic ring screening fixture and a fiber optic stress analyzer, is connected. The aging chamber is equipped with a temperature control component to achieve precise temperature regulation. The specific process is as follows: the aging chamber temperature is set to 50℃±1℃, and the fiber optic ring is rotated at a speed of 3 rpm for 24 hours at room temperature. After aging, the zero-bias stability and stress distribution parameters of the fiber optic ring are collected sequentially at three temperature points: 25℃, 60℃, and -40℃. If all three indicators simultaneously meet the preset conditions, the process proceeds to the next stage; otherwise, the room temperature aging process is repeated. For the calibrated fiber optic rings, a curing process is performed. First, a first high-temperature aging process is carried out at 85℃±1℃ for 48 hours. Then, high and low temperature cycling aging is conducted from 85℃±1℃ to -55℃±1℃ with a temperature change rate ≥5℃ / min. After aging, the above three-temperature zone parameter calibration is repeated. If the parameters meet the standards, the process proceeds to the next stage; otherwise, the rings are returned to the room temperature aging stage. For the calibrated fiber optic rings, bonding treatment is performed. Then, a second high-temperature aging process is carried out at 85℃±1℃ for 48 hours. After aging, the three-temperature zone parameter calibration is repeated again. If the parameters meet the standards, the entire aging process is completed; otherwise, the rings are returned to the room temperature aging stage.

[0009] This solution is a dedicated aging solution for discrete components of the fiber optic ring, which has the following three major shortcomings: (a) The aging coverage is limited, with the aging process designed only for the fiber optic ring as an independent component, without constructing a systematic aging system covering all core components of the gyroscope; (b) The performance optimization dimensions are narrow, with aging research and performance control conducted only from the perspective of optical characteristics, without covering the optoelectronic and electrical characteristics of other components in the gyroscope, resulting in significant limitations in the optimization dimensions; (c) System-level collaborative optimization is lacking, without considering the matching and adaptation characteristics between multiple components within the gyroscope, making it impossible to achieve system-level performance synergy improvement and ensuring the performance stability of the entire system under all operating conditions.

[0010] In summary, existing aging schemes have failed to specifically address the differentiated stress release and synergistic aging requirements of the two core components in silicon photonic gyroscopes: the silicon photonic chip assembly and the polarization-maintaining fiber ring assembly. This results in poor long-term performance stability improvement for silicon photonic gyroscopes and may even cause permanent damage to optical performance. Summary of the Invention

[0011] The purpose of this invention is to provide an aging method and apparatus for silicon optical gyroscopes, in order to solve the problem that the existing technology does not effectively improve the long-term performance stability of silicon optical gyroscopes, and may even cause permanent damage to their optical performance.

[0012] To achieve the above objectives, the first aspect of the present invention adopts the following technical solution: an aging method for a silicon photonic gyroscope, wherein the silicon photonic gyroscope comprises a silicon photonic chip assembly and an optical fiber ring assembly, comprising the following stages:

[0013] The first stage involves placing the silicon optical gyroscope to be aged in a high and low temperature test chamber. Under static conditions without power, the temperature is raised to 65±2℃ at a preset heating rate and stored at a constant temperature for a first preset time. Then, the temperature is lowered to 25±2℃ at a preset cooling rate and kept at that temperature.

[0014] In the second stage, under a static state without power, the silicon optical gyroscope undergoes 15-20 complete high and low temperature cycles. Each high and low temperature cycle includes a process of heating from 25±2℃ to the high temperature extreme point at a rate of 0.5-2℃ / min, holding at the high temperature extreme point, cooling from the high temperature extreme point to the low temperature extreme point at a rate of 0.5-2℃ / min, holding at the low temperature extreme point, and heating from the low temperature extreme point to 25±2℃ at a rate of 0.5-2℃ / min. The temperature of the high temperature extreme point is 70-85℃, and the temperature of the low temperature extreme point is -45 to -40℃.

[0015] In the third stage, the silicon optical gyroscope is placed in a constant temperature environment of 55±2℃, and the rated working voltage is applied for full-power continuous aging. The zero-bias output data of the silicon optical gyroscope is collected at preset time intervals and its performance is monitored.

[0016] In the fourth stage, under a static state without power, the temperature is increased to 45±2℃ at a heating rate of 0.3-0.8℃ / min, and stored at a constant temperature for a second preset time. Then, the temperature is decreased to 25±2℃ at the same cooling rate of 0.3-0.8℃ / min and kept at that temperature.

[0017] Furthermore, the first preset duration is 72±2h, the preset heating rate and preset cooling rate are both 0.5-1.5℃ / min, and the heat preservation duration is 1.5-2.5h.

[0018] Furthermore, after the first stage is completed, the silicon photonic gyroscope is taken out for the first intermediate performance test, and unqualified products with sudden performance changes are eliminated based on the results of the first intermediate performance test; the first intermediate performance test includes room temperature zero bias stability test, full temperature zero bias stability test, scaling factor nonlinearity test and scaling factor asymmetry test.

[0019] Furthermore, after the second stage is completed, the temperature is reduced to 25±2℃ at a rate of 0.5-2℃ / min and kept at that temperature for 1.5-2.5h. The silicon optical gyroscope is then removed for a second intermediate performance test. Based on the results of the second intermediate performance test, defective products with sudden performance changes are eliminated.

[0020] Furthermore, the aging time in the third stage is 120h±4h, with a preset time of 0.8-1.2h.

[0021] Furthermore, after the third stage is completed, the power supply is disconnected, and the temperature is allowed to drop naturally to 25±2℃. The silicon photonic gyroscope is then removed for a third intermediate performance test. Based on the results of the third intermediate performance test, defective products with sudden performance changes are eliminated.

[0022] Furthermore, the second preset duration is 45-50 hours.

[0023] Furthermore, after the fourth stage is completed, the silicon photonic gyroscope is taken out for final performance testing, and unqualified products with sudden performance changes are eliminated based on the results of the final performance test.

[0024] Furthermore, a preparatory stage is included before the first stage, which includes:

[0025] The silicon photonic gyroscope to be aged is assembled, debugged, and initially inspected. Then, the silicon photonic gyroscope is placed in a high and low temperature test chamber, and the power supply and performance monitoring lines are connected to complete the equipment debugging. Then, the initial performance test is carried out in a standard atmospheric environment.

[0026] The second aspect of this invention adopts the following technical solution: an aging apparatus for implementing the aging method of the silicon photonic gyroscope described in the first aspect of this invention, comprising:

[0027] High and low temperature test chamber, used to contain silicon optical gyroscopes to be aged and provide a controlled temperature environment;

[0028] A temperature control system is electrically connected to the temperature control interface of the high and low temperature test chamber and is used to control the temperature change inside the high and low temperature test chamber. The temperature control system can achieve a temperature change rate control of 0.3-2℃ / min.

[0029] The power supply system is electrically connected to the power supply interface of the silicon photonic gyroscope and is used to apply the rated operating voltage to the silicon photonic gyroscope in the third stage to achieve full power supply.

[0030] A performance monitoring system is connected to the signal output interface of the silicon photonic gyroscope to collect the zero-bias output data of the silicon photonic gyroscope in real time.

[0031] A data recording system, connected to the performance monitoring system, is used to record and store the collected performance data;

[0032] The temperature control system is communicatively connected to the performance monitoring system for synchronizing temperature and performance data.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. This invention comprehensively addresses all core causes of performance drift in silicon photonic gyroscopes through a four-stage, step-by-step targeted treatment: the residual stress release rate of the fiber optic ring reaches over 98%, the stress release rate of the silicon photonic chip interface / waveguide reaches over 95%, and the electrical parameters of active devices enter the stable range ahead of schedule. Compared with traditional aging methods, the silicon photonic gyroscope treated by this invention shows a more than 25% improvement in room temperature zero-bias stability after 1200 hours of long-term storage, a more than 50% reduction in long-term scaling factor drift, and a more than 28% improvement in full-temperature zero-bias stability. Compared with similar patented solutions, the room temperature zero-bias stability after 1200 hours of long-term storage is improved by over 14%, the long-term scaling factor drift is reduced by over 20%, and the full-temperature zero-bias stability is improved by over 25%. This completely solves the industry pain point of continuous performance drift in silicon photonic gyroscopes during long-term use after leaving the factory.

[0035] 2. The entire process parameters of this invention strictly comply with the military standard GJB150A-2009. Through stress release by high and low temperature cycling across the entire temperature range, the performance stability of the product is greatly improved within the full military operating temperature range of -45℃ to +85℃, which can meet the stringent environmental requirements of high-end scenarios such as aerospace and military guidance.

[0036] 3. The step-by-step synergy of this invention ensures that the stress release of each silicon photonic gyroscope is sufficient and uniform, the standard deviation of the zero bias stability of batch products is reduced to 0.086° / h, and the consistency is improved by more than 52%, which solves the core problem of poor batch consistency in the mass production of silicon photonic gyroscopes and improves the yield of mass production.

[0037] 4. This invention optimizes the aging time and cycle number of each stage through extensive testing. Furthermore, the early determination mechanism for the stable inflection point in the third stage further shortens the aging time, balancing aging effectiveness with production efficiency. Compared to existing solutions, although the basic duration is slightly increased, it completely avoids the problems of rework and returns caused by performance degradation after the product leaves the factory, reducing the overall lifecycle production cost and fully adapting to the needs of industrialized mass production. Attached Figure Description

[0038] Figure 1 This is a flowchart of the process flow in this invention;

[0039] Figure 2 This is a trend graph showing the mean room temperature stability of the experimental group, control group 1, and control group 2 in this invention.

[0040] Figure 3 This is a trend chart of the mean values ​​of the full-temperature zero-bias stability of the experimental group, control group 1, and control group 2 in this invention;

[0041] Figure 4 This is a trend graph showing the average drift of the scaling factor for the experimental group, control group 1, and control group 2 in this invention.

[0042] Figure 5 This is a trend graph of the scaling factor measurement values ​​of a single product in the experimental group, control group 1, and control group 2 in this invention;

[0043] Figure 6 This is a distribution diagram of the zero-bias stability data of the experimental group, control group 1, and control group 2 in this invention. Detailed Implementation

[0044] The present invention will be further described in detail below through specific embodiments:

[0045] In this invention, the silicon photonic chip assembly comprises various materials and structures such as silicon-based waveguides, bonding interfaces, active device light sources, active device modulators, and active device detectors. The fiber optic ring assembly comprises structures such as polarization-maintaining fiber, acrylate coating, and curing adhesive layer. This invention is based on the differentiated aging characteristics of the silicon photonic chip assembly and the fiber optic ring assembly, employing a "step-by-step collaborative, phased targeted treatment" end-to-end aging scheme. Through four core stages, it targets and addresses the core needs of residual stress release in the fiber optic ring, stress balance between the two components, electrical stability of the silicon chip active devices, and overall performance curing, thereby achieving comprehensive performance stabilization of the silicon photonic gyroscope.

[0046] Specifically, such as Figure 1 As shown, the aging method for silicon optical gyroscopes provided by the present invention includes a pre-preparation stage, a pre-baking and pre-treatment stage, a high and low temperature cyclic aging stage, a constant temperature energized aging stage, and a stabilization annealing finishing stage.

[0047] The preparatory stage includes:

[0048] (1) Silicon optical gyroscopes to be aged need to complete the assembly, debugging and initial inspection of the whole machine, and products with appearance defects and electrical connection failures should be eliminated;

[0049] (2) Under standard atmospheric conditions (temperature 25±2℃, relative humidity 50%±10%, atmospheric pressure 101.3kPa), complete the initial performance test. The initial performance test items include: room temperature zero bias stability test (10s, 1σ), full temperature zero bias stability test (100s, 1σ, -45℃ to +65℃), scaling factor nonlinearity test, and scaling factor asymmetry test. Record all initial data.

[0050] (3) Place the silicon photonic gyroscope into the high and low temperature test chamber, connect the power supply and performance monitoring lines, and complete the equipment debugging.

[0051] The pre-processing stage is the foundation of the aging process. Through assembly, debugging, and initial inspection of the entire machine, products with obvious appearance defects and electrical connection faults can be eliminated, preventing unqualified products from entering the aging process. By connecting the power supply and performance monitoring lines and completing equipment debugging, the stability of the power supply and the accuracy of performance monitoring during the subsequent aging process can be guaranteed. By completing the initial performance test in a standard atmospheric environment and recording all initial data, a benchmark can be provided for the intermediate and final performance tests in subsequent stages, facilitating the evaluation of the aging effect and the determination of product qualification.

[0052] The pre-drying and pretreatment stage includes:

[0053] The silicon optical gyroscope to be aged is placed in a high and low temperature test chamber. Under static conditions without power, it is heated to 65±2℃ at a preset heating rate and stored at this temperature for 72±2 hours. Then, it is cooled to 25±2℃ at a preset cooling rate and held at that temperature. In this embodiment, both the preset heating rate and the preset cooling rate are 0.5-1.5℃ / min, preferably 1℃ / min; the holding time is 1.5-2.5 hours, preferably 2 hours.

[0054] This stage specifically targets the initial stress release of the fiber optic ring assembly. 65℃ is the glass transition temperature (T0) of the polarization-maintaining fiber's acrylate coating. g The optimal stress release temperature (≈80℃) allows the curing adhesive molecular chains to slowly relax and uniformly release the residual stress and internal stress introduced during the winding process, without causing the adhesive layer to age and become brittle. At the same time, this temperature will not cause any thermal damage to the bonding interface, waveguide structure, or active devices of the silicon photonic chip, perfectly avoiding the conflict between the aging conditions of the two major components, laying the foundation for subsequent cyclic aging, and avoiding the sudden change in fiber birefringence caused by stress concentration during temperature changes.

[0055] After completing the pre-drying and pretreatment stage, the following first post-operation must be performed before proceeding to the high and low temperature cyclic aging stage.

[0056] First post-operation: Take out the silicon photonic gyroscope and perform the first intermediate performance test. Based on the results of the first intermediate performance test, reject unqualified products with sudden performance changes. The first intermediate performance test is the same as the initial performance test.

[0057] The high and low temperature cyclic aging stage includes:

[0058] In a static, unpowered state, the silicon optical gyroscope undergoes multiple complete high-low temperature cycles. Each high-low temperature cycle includes a process of heating from 25±2℃ to a high-temperature extreme point at a first temperature change rate, holding at the high-temperature extreme point, cooling from the high-temperature extreme point to a low-temperature extreme point at the first temperature change rate, holding at the low-temperature extreme point, and then heating from the low-temperature extreme point to 25±2℃ at the first temperature change rate. The temperature of the high-temperature extreme point is 70-85℃, preferably 85℃; the temperature of the low-temperature extreme point is -45 to -40℃, preferably -45℃; the first temperature change rate is 0.5-2℃ / min, preferably 1℃ / min; and the number of high-low temperature cycles is 15-20 times, preferably 15 times.

[0059] This stage is the core collaborative processing stage, which completely solves the pain point that existing technologies cannot simultaneously address the stress release of the two major components:

[0060] (a) For silicon photonic chip components: The low temperature of around -45°C can fully expose the thermal mismatch stress between silicon-based materials, packaging shells, and bonding solders, while the high temperature of around 85°C can fully release the internal stress of silicon photonic waveguides and the stress of chip-fiber coupling adhesive layers. Through multiple slow temperature cycles, the interface stress is gradually relaxed, which solves the problems of waveguide coupling efficiency drift and increased polarization-related loss during long-term use.

[0061] (b) For fiber optic ring components: multiple slow temperature change cycles allow the residual stress of the entire fiber optic ring to be released gradually and uniformly in the entire temperature range, solving the problem of uneven stress release caused by single-step high-temperature storage. The slow temperature change rate of 1℃ / min completely avoids the irreversible thermal stress introduced by rapid temperature change.

[0062] (c) Basis for parameter optimization: After extensive testing, the stress release rate of the two major components in the first cycle is less than 70%, while the stress release rate can reach more than 95% after 15 cycles. After more than 20 cycles, the stress release rate increases by less than 1%, which will increase the risk of adhesive layer aging. 15 cycles is the optimal value that balances effect and efficiency.

[0063] After completing the high and low temperature aging stage, the following second operation must be performed before proceeding to the constant temperature and power-on aging stage.

[0064] The second post-operation involves cooling the silicon gyroscope to 25±2℃ at a rate of 0.5-2℃ / min and holding it at that temperature for 1.5-2.5 hours. The gyroscope is then removed for a second intermediate performance test. Products exhibiting sudden performance changes are discarded based on the results of this second intermediate performance test. Preferably, the temperature is lowered to 25±2℃ at a rate of 1℃ / min and held for 2 hours before the second intermediate performance test. This second intermediate performance test is identical to the initial performance test.

[0065] The constant temperature and electric aging stage includes:

[0066] The silicon optical gyroscope was placed in a constant temperature environment of 55±2℃ and subjected to full-power continuous aging at its rated operating voltage for 120h±4h. Zero-bias output data of the silicon optical gyroscope was collected and its performance monitored at preset time intervals. The preset time was 0.8-1.2h, preferably 1h.

[0067] This phase specifically addresses the electrical drift problem of active devices in silicon photonic chips, a problem completely ignored by existing technologies. Light sources, modulators, and detectors on silicon chips exhibit electrical characteristic drift during long-term powered operation, including output power drift, half-wave voltage variation, and decreased responsivity. This type of drift cannot be exposed or stabilized during non-powered aging. A constant temperature of approximately 55°C, near the upper limit of the gyroscope's rated operating temperature, accelerates the electrical aging of active devices, exposing potential early failures without reducing device lifespan. Approximately 120 hours of full-power aging allows the electrical parameters of active devices to quickly enter a stable range. When the average fluctuation range of the gyroscope's zero-bias output over 1 hour is within 0.05° / h for three consecutive sets of data acquisitions, the electrical characteristics are considered stable, allowing for earlier entry into the next stage and improved production efficiency. This phase also simultaneously achieves the final stress relaxation of the fiber optic ring assembly, completing the secondary coordinated stabilization of the two major components.

[0068] After completing the constant temperature and electric aging stage, the following third operation must be performed first, followed by the stabilization annealing final stage.

[0069] The third follow-up procedure: Disconnect the power supply, allow the temperature to cool naturally to 25℃±2℃, complete the third intermediate performance test, record the data, and eliminate defective products with sudden performance changes based on the results of the third intermediate performance test. The third intermediate performance test is the same as the initial performance test.

[0070] The stabilization annealing final stage includes:

[0071] In the non-powered static state, heat up to 45 ± 2 °C at the heating rate of the second temperature change rate, store at a constant temperature for the second preset duration, and then cool down to 25 ± 2 °C at the cooling rate of the second temperature change rate and keep warm. Among them, the second temperature change rate is 0.3 - 0.8 °C / min, preferably 0.5 °C / min; the second preset duration is 45 - 50 h, preferably 48 h; the heat preservation duration is 3 - 5 h, preferably 4 h.

[0072] This stage is the performance curing final stage, which solves the problems of the tiny imbalance in the internal stress distribution of the gyro after the previous aging and the residual thermal stress of the active devices after the power-on aging. The extremely slow temperature change rate of about 0.5 °C / min and the moderate temperature of about 45 °C can make the stress distribution of all materials (silicon chips, optical fibers, adhesive layers, housings) of the gyro reach the final equilibrium state, completely cure the aging effects of the previous three stages, avoid the long-term performance drift caused by the tiny stress imbalance after the product leaves the factory, and achieve the "shaping" of the gyro performance.

[0073] After completing the stabilization annealing final stage, take out the gyro and complete the final performance test. If the comparison with the initial data meets the product technical requirements, it is judged as qualified for aging, and the unqualified products with performance mutations are excluded. The final performance test is the same as the initial performance test.

[0074] The following will be explained with specific embodiments.

[0075] Embodiment 1

[0076] An aging method for a silicon optical gyro includes a pre-preparation stage, a pre-drying pretreatment stage, a high and low temperature cycling aging stage, a constant temperature power-on aging stage, and a stabilization annealing final stage.

[0077] Among them, the pre-preparation stage includes:

[0078] (1) The silicon optical gyro to be aged needs to complete the whole machine assembly, debugging and initial inspection, and exclude the products with appearance defects and electrical connection failures;

[0079] (2) In the standard atmospheric environment, complete the initial performance test. The test items of the initial performance test include: room temperature zero bias stability test (10 s, 1σ), full temperature zero bias stability test (100 s, 1σ, -45 °C - +65 °C), scale factor nonlinearity test, scale factor asymmetry test, and record all initial data;

[0080] (3) Put the silicon optical gyro into the high and low temperature test chamber, connect the power supply and performance monitoring lines, and complete the equipment debugging.

[0081] The pre-drying pretreatment stage includes:

[0082] The silicon optical gyroscope to be aged was placed in a high and low temperature test chamber. Under static conditions without power, the temperature was increased to 65±2℃ at a rate of 1℃ / min and stored at a constant temperature for 72±2h. Then, the temperature was decreased to 25±2℃ at a rate of 1℃ / min and kept at that temperature for 2h.

[0083] After completing the pre-drying and pretreatment stage, the following first post-operation must be performed before proceeding to the high and low temperature cyclic aging stage.

[0084] First post-operation: Take out the silicon photonic gyroscope and perform the first intermediate performance test. Based on the results of the first intermediate performance test, reject unqualified products with sudden performance changes.

[0085] The high and low temperature cyclic aging stage includes:

[0086] In a static state without power, the silicon optical gyroscope was subjected to 15 complete high and low temperature cycles. Each high and low temperature cycle included a process of heating from 25±2℃ to 85℃ at a rate of 1℃ / min, holding at 85℃ for 4 hours, cooling from 85℃ to -45℃ at a rate of 1℃ / min, holding at -45℃ for 4 hours, and heating from -45℃ to 25±2℃ at a variable rate of 1℃ / min.

[0087] After completing the high and low temperature aging stage, the following second operation must be performed before proceeding to the constant temperature and power-on aging stage.

[0088] The second post-operation: Cool down to 25±2℃ at a rate of 1℃ / min, keep warm for 2 hours, take out the silicon optical gyroscope and conduct a second intermediate performance test, and remove unqualified products with sudden performance changes based on the results of the second intermediate performance test.

[0089] The constant temperature and electric aging stage includes:

[0090] The silicon optical gyroscope was placed in a constant temperature environment of 55±2℃ and subjected to full-power continuous aging for 120 hours with the rated operating voltage applied. The zero-bias output data of the silicon optical gyroscope was collected every 1 hour and its performance was monitored.

[0091] After completing the constant temperature and electric aging stage, the following third operation must be performed first, followed by the stabilization annealing final stage.

[0092] Third post-operation: Disconnect the power supply, allow it to cool naturally to 25℃±2℃, complete the third intermediate performance test, record the data, and eliminate unqualified products with sudden performance changes based on the results of the third intermediate performance test.

[0093] The stabilization annealing final stage includes:

[0094] Under static conditions without power, the temperature is increased to 45±2℃ at a heating rate of 0.5℃ / min, and stored at a constant temperature for 48h. Then, the temperature is decreased to 25±2℃ at a cooling rate of 0.5℃ / min and held at that temperature for 4h.

[0095] After the stabilization annealing stage is completed, the gyroscope is taken out to complete the final performance test. If the data is consistent with the product's technical requirements, it is judged to be qualified for aging, and unqualified products with sudden performance changes are discarded.

[0096] Comparative Example 1

[0097] The silicon photonic gyroscope is aged using the traditional fiber optic gyroscope aging scheme described in the background technology.

[0098] Comparative Example 2

[0099] The silicon optical gyroscope was aged using the aging method described in CN115638781B.

[0100] Thirty silicon photonic gyroscopes of the same batch and specifications were selected and randomly divided into an experimental group (Example 1), a control group 1 (Comparative Example 1), and a control group 2 (Comparative Example 2), with 10 gyroscopes in each group. After aging, a 1200-hour long-term storage test at room temperature was conducted. During the test, a room temperature zero bias test and a scaling factor test were performed on the gyroscopes every 240 hours. The core performance comparison is shown in Table 1.

[0101] Table 1 Comparison of Core Performance

[0102]

[0103] Combined with appendix Figure 2 , Figure 3 , Figure 4 , Figure 5 as well as Figure 6 The curves show that the zero-bias stability and scaling factor of the silicon photonic gyroscope in the experimental group are almost horizontal with no obvious drift as a function of storage time; while the curves of the control groups 1 and 2 show a significant upward trend, indicating significant long-term performance degradation. This fully verifies the effect of the present invention on improving the long-term performance stability and batch performance consistency of silicon photonic gyroscopes.

[0104] Note 1: The aging protocol for control group 2 was slightly adjusted during the experiment to adapt to the overall system. In the original protocol, the fiber optic ring was fixed on a rotating shaft inside the aging chamber, causing the fiber optic ring to rotate; in the experiment, it was adjusted so that the silicon photonic gyroscope was fixed on a temperature-controlled turntable using a fixture, causing the entire unit to rotate.

[0105] Note 2: The full-temperature zero-bias test is only performed before and after long-term storage to avoid affecting the accuracy of the experiment due to stress release from multiple temperature cycles. Figure 5The data on the trend of the scaling factor measurement value of a single product in the study were obtained from a sample randomly selected from each of the experimental group, control group 1, and control group 2.

[0106] Example 2

[0107] This embodiment provides an aging apparatus for implementing the aging method of the silicon photonic gyroscope described in section 1. The aging apparatus includes a high and low temperature test chamber, a temperature control system, a power supply system, a performance monitoring system, and a data recording system. The high and low temperature test chamber is used to contain the silicon photonic gyroscope to be aged and provide a controllable temperature environment. The temperature control system is electrically connected to the temperature control interface of the high and low temperature test chamber and is used to control the temperature changes within the test chamber. The temperature control system can achieve a temperature change rate control of 0.3-2℃ / min.

[0108] The power supply system is electrically connected to the power supply interface of the silicon photonic gyroscope, and is used to apply the rated operating voltage to the silicon photonic gyroscope to achieve full-power operation during the constant-temperature aging stage. The performance monitoring system is connected to the signal output interface of the silicon photonic gyroscope, and is used to acquire the zero-bias output data of the silicon photonic gyroscope in real time. The data recording system is connected to the performance monitoring system, and is used to record and store the acquired performance data. The temperature control system is communicatively connected to the performance monitoring system, and is used to synchronize temperature data with performance data.

[0109] The temperature control system includes a temperature sensor, a PID temperature controller, a heating unit, and a cooling unit, enabling precise temperature control within the range of -45℃ to +85℃, with a temperature control accuracy of ±2℃. The temperature sensor monitors the temperature inside the high and low temperature test chamber in real time, and the PID temperature controller controls the operating status of the heating and cooling units based on the feedback signal from the temperature sensor, achieving precise temperature control. The temperature control accuracy of ±2℃ meets the temperature accuracy requirements of the four-stage aging process.

[0110] The performance monitoring system includes a signal acquisition module, a data processing module, and a display module. The signal acquisition module automatically acquires 1 hour of zero-bias output data from the silicon photonics gyroscope every 24 hours. The data processing module calculates the mean fluctuation range in real time. When three consecutive sets of mean fluctuation ranges are ≤0.05° / h, the display module automatically triggers an early warning. The signal acquisition module connects to the signal output interface of the silicon photonics gyroscope and automatically acquires 1 hour of zero-bias output data every 24 hours without manual intervention. The data processing module processes the acquired zero-bias output data in real time and calculates the mean fluctuation range.

[0111] When the average fluctuation range of three consecutive sets is ≤0.05° / h, the electrical characteristics are considered to have stabilized. The display module automatically triggers an early warning when it detects stable electrical characteristics, reminding the operator to end stage three early and proceed to stage four, thus achieving intelligent and efficient aging process.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An aging method for a silicon photonic gyroscope, the silicon photonic gyroscope comprising a silicon photonic chip assembly and an optical fiber ring assembly, characterized in that, Includes the following stages: The first stage involves placing the silicon optical gyroscope to be aged in a high and low temperature test chamber. Under static conditions without power, the temperature is raised to 65±2℃ at a preset heating rate and stored at a constant temperature for a first preset time. Then, the temperature is lowered to 25±2℃ at a preset cooling rate and kept at that temperature. In the second stage, under a static state without power, the silicon optical gyroscope undergoes 15-20 complete high and low temperature cycles. Each high and low temperature cycle includes a process of heating from 25±2℃ to the high temperature extreme point at a rate of 0.5-2℃ / min, holding at the high temperature extreme point, cooling from the high temperature extreme point to the low temperature extreme point at a rate of 0.5-2℃ / min, holding at the low temperature extreme point, and heating from the low temperature extreme point to 25±2℃ at a rate of 0.5-2℃ / min. The temperature of the high temperature extreme point is 70-85℃, and the temperature of the low temperature extreme point is -45 to -40℃. In the third stage, the silicon optical gyroscope is placed in a constant temperature environment of 55±2℃, and the rated working voltage is applied for full-power continuous aging. The zero-bias output data of the silicon optical gyroscope is collected at preset time intervals and its performance is monitored. In the fourth stage, under a static state without power, the temperature is increased to 45±2℃ at a heating rate of 0.3-0.8℃ / min, and stored at a constant temperature for a second preset time. Then, the temperature is decreased to 25±2℃ at the same cooling rate of 0.3-0.8℃ / min and kept at that temperature.

2. The aging method for a silicon optical gyroscope according to claim 1, characterized in that, The first preset duration is 72±2h, the preset heating rate and preset cooling rate are both 0.5-1.5℃ / min, and the heat preservation duration is 1.5-2.5h.

3. The aging method for a silicon optical gyroscope according to claim 1 or 2, characterized in that, After the first stage is completed, the silicon photonic gyroscope is taken out for the first intermediate performance test. Based on the results of the first intermediate performance test, unqualified products with sudden performance changes are eliminated. The first intermediate performance test includes room temperature zero bias stability test, full temperature zero bias stability test, scaling factor nonlinearity test and scaling factor asymmetry test.

4. The aging method for a silicon optical gyroscope according to claim 1, characterized in that, After the second stage is completed, the temperature is reduced to 25±2℃ at a rate of 0.5-2℃ / min and kept at that temperature for 1.5-2.5h. The silicon optical gyroscope is then removed for a second intermediate performance test. Based on the results of the second intermediate performance test, defective products with sudden performance changes are eliminated.

5. The aging method for a silicon optical gyroscope according to claim 1, characterized in that, The third stage of electrical aging takes 120h ± 4h, with a preset time of 0.8-1.2h.

6. An aging method for a silicon optical gyroscope according to claim 1 or 5, characterized in that, After the third stage is completed, the power supply is disconnected, and the temperature is allowed to drop naturally to 25±2℃. The silicon photonic gyroscope is then removed for a third intermediate performance test. Based on the results of the third intermediate performance test, defective products with sudden performance changes are eliminated.

7. The aging method for a silicon optical gyroscope according to claim 1, characterized in that, The second preset duration is 45-50 hours.

8. An aging method for a silicon optical gyroscope according to claim 1 or 7, characterized in that, After the fourth stage is completed, the silicon photonic gyroscope is taken out for final performance testing, and unqualified products with sudden performance changes are eliminated based on the results of the final performance test.

9. An aging method for a silicon optical gyroscope according to any one of claims 1, 2, 4, 5 or 7, characterized in that, The first stage is preceded by a preparatory stage, which includes: The silicon photonic gyroscope to be aged is assembled, debugged, and initially inspected. Then, the silicon photonic gyroscope is placed in a high and low temperature test chamber, and the power supply and performance monitoring lines are connected to complete the equipment debugging. Then, the initial performance test is carried out in a standard atmospheric environment.

10. An aging apparatus for implementing the aging method of any one of claims 1-9 for a silicon optical gyroscope, characterized in that, include: High and low temperature test chamber, used to contain silicon optical gyroscopes to be aged and provide a controlled temperature environment; A temperature control system is electrically connected to the temperature control interface of the high and low temperature test chamber and is used to control the temperature change inside the high and low temperature test chamber. The temperature control system can achieve a temperature change rate control of 0.3-2℃ / min. The power supply system is electrically connected to the power supply interface of the silicon photonic gyroscope and is used to apply the rated operating voltage to the silicon photonic gyroscope in the third stage to achieve full power supply. A performance monitoring system is connected to the signal output interface of the silicon photonic gyroscope to collect the zero-bias output data of the silicon photonic gyroscope in real time. A data recording system, connected to the performance monitoring system, is used to record and store the collected performance data; The temperature control system is communicatively connected to the performance monitoring system for synchronizing temperature and performance data.

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