Optical gyroscope system based on resonator real-time temperature detection control

Abstract

The application discloses a kind of optical gyro systems based on resonant cavity real-time temperature detection control, comprising: light source module, modulation module, resonant cavity, frequency locking module, drive control module and temperature control module;Light beam emitted by light source module is divided into two ways in modulation module, and frequency locking module feeds back first light beam information to light source module to control the center frequency of light beam emitted by light source module, and the frequency is locked on the resonant frequency of resonant cavity;Temperature control module controls the temperature of resonant cavity according to second light beam information, and drive control module controls modulation module according to second light beam information to realize the frequency movement of light beam emitted by light source module.The optical gyro system of the application solves the problem that the existing resonant optical gyro system is excited by two polarization states due to resonant cavity, which affects the long-term working stability of optical gyro when temperature changes.

Description

Technical Field

[0001] This invention relates to the field of resonant optical gyroscope technology, and in particular to an optical gyroscope system based on real-time temperature detection and control of the resonant cavity. Background Technology

[0002] Inertial navigation technology, due to its high degree of stealth and ability to acquire motion information autonomously, has wide applications in numerous fields, including military defense and national economy. Currently, optical gyroscopes, as the most important component of inertial navigation systems, have a significant impact on their performance; therefore, optical gyroscopes have become a key focus of research and development for various research institutions.

[0003] Resonant optical gyroscopes are a type of optical gyroscope developed based on laser gyroscopes and interferometric fiber optic gyroscopes, driven by the demand for high-precision, miniaturized, and low-cost gyroscopes in inertial navigation systems. Using passive optical fiber or waveguide resonant cavities as the sensing medium, resonant optical gyroscopes combine the resonance principle of laser gyroscopes with the passive structural characteristics of interferometric fiber optic gyroscopes. They can effectively reduce fiber length while achieving high precision, offering advantages such as passive structure, high precision, small size, and low cost, making them one of the important directions for the development of inertial devices both domestically and internationally.

[0004] In reality, besides the theoretical sensitivity limitation imposed by detector shot noise, the detection accuracy of resonant optical gyroscopes is also constrained by back reflection / scattering noise and temperature-related polarization noise in the actual system. After years of research, a relatively complete theoretical and technical framework exists for addressing back reflection / scattering noise, which affects the detection accuracy of resonant optical gyroscopes, both in terms of its noise mechanism and suppression measures. Due to birefringence, two orthogonal intrinsic polarization states are excited within the resonant cavity. Each polarization state has its own resonance curve and resonant frequency, and the total output signal of the resonant cavity is the superposition of the corresponding output resonance curves of the two intrinsic polarization states. Changes in external environmental factors such as temperature can affect the superposition and interference effects of the resonant light waves corresponding to the two intrinsic polarization states, leading to detection errors at the resonant frequency points.

[0005] Compared to backscattering / reflection noise, there has been no substantial progress in addressing polarization noise, which affects the long-term stability of resonant optical gyroscopes. Optical gyroscopes based on fiber optic ring resonator structures can reduce polarization noise by employing measures such as 90° fiber axis rotation fusion splicing, adding a polarizer within the cavity, and using single-polarization fibers. However, in actual experiments, it has been found that polarization noise cannot be completely suppressed and is still affected by temperature. For optical gyroscopes based on wave resonators, although this can be achieved by inserting a half-wave plate into the resonator, it undoubtedly increases the total loss of the resonator and reduces the theoretical sensitivity of the optical gyroscope. Another effective method for suppressing polarization noise is to make the resonator support only a single polarization state of light transmission, such as using a silicon nitride waveguide with extremely low aspect ratio polarization properties to fabricate the resonator. Although reports indicate that single polarization of the resonator has been achieved, its excessively high transmission loss limits the detection accuracy of the optical gyroscope. Therefore, existing measures cannot simultaneously meet the requirements of low resonator loss and single polarization. Since the materials used to make the resonant cavity all have birefringence effect, which is temperature-dependent, the position of the resonance curve excited in the resonant cavity will change when the temperature changes. At a certain temperature, polarization interference peaks and polarization interference valleys will be generated. The position near the interference peaks and valleys will affect the detection accuracy of the resonant optical gyroscope.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide an optical gyroscope system based on real-time temperature detection and control of a resonant cavity, which solves the problem that the existing resonant optical gyroscope system suffers from the long-term operational stability of the optical gyroscope due to the two polarization states excited by the resonant cavity.

[0008] To achieve the above objectives, embodiments of the present invention provide an optical gyroscope system based on real-time temperature detection and control of a resonant cavity, comprising: a light source module, a modulation module, a resonant cavity, a frequency locking module, a drive control module, and a temperature control module; the light source module is connected to the modulation module; the modulation module is connected to the resonant cavity; the resonant cavity is connected to the frequency locking module, the drive control module, and the temperature control module respectively; the frequency locking module is also connected to the light source module; the drive control module is also connected to the modulation module; the temperature control module is connected to the resonant cavity; wherein, the light beam emitted by the light source module is contained within the modulation module. The beam is split into two paths. The first beam is output through the resonant cavity to the frequency locking module, which feeds back the information of the first beam to the light source module to control the center frequency of the beam emitted by the light source module and locks this frequency to the resonant frequency of the resonant cavity. The second beam is output through the resonant cavity to the temperature control module, which controls the temperature of the resonant cavity according to the information of the second beam. The second beam is also output through the resonant cavity to the drive control module, which controls the modulation module to shift the frequency of the beam emitted by the light source module according to the information of the second beam.

[0009] In one or more embodiments of the present invention, the system further includes a signal acquisition module connected to the drive control module to acquire a first frequency of the second beam that has not passed through the resonant cavity and a second frequency of the second beam that has passed through the resonant cavity. The signal acquisition module acquires the angular velocity information of the gyroscope system by acquiring the frequency difference signal between the first frequency and the second frequency.

[0010] In one or more embodiments of the present invention, the system further includes a coupling module, the coupling module including a first coupler and a second coupler, the modulation module being connected to the resonant cavity through the first coupler, and the resonant cavity being connected to the frequency locking module, the drive control module and the temperature control module through the second coupler.

[0011] In one or more embodiments of the present invention, the system further includes a detection module, the detection module including a first photodetector and a second photodetector, the second coupler being connected to the frequency locking module through the first photodetector, and the second coupler being connected to the drive control module and the temperature control module through the second photodetector.

[0012] In one or more embodiments of the present invention, the light source module includes a fiber laser and an optical isolator, wherein the output end of the fiber laser is connected to the input end of the optical isolator.

[0013] In one or more embodiments of the present invention, the modulation module includes a lithium niobate phase modulator, the first input terminal and the second input terminal of the lithium niobate phase modulator are both connected to the output terminal of the optical isolator, and the first output terminal and the second output terminal of the lithium niobate phase modulator are both connected to the input terminal of the first coupler.

[0014] In one or more embodiments of the present invention, the frequency locking module includes a first analog-to-digital converter, a first signal demodulation device, a first PI integrator, and a first digital-to-analog converter connected in sequence. The first analog-to-digital converter is connected to the first photodetector, and the first digital-to-analog converter is connected to the fiber laser.

[0015] In one or more embodiments of the present invention, the drive control module includes a second analog-to-digital converter, a second signal demodulation device, a second PI integrator, a frequency shift driver, and a second digital-to-analog converter connected in sequence. The second analog-to-digital converter is connected to the second photodetector, and the second digital-to-analog converter is connected to the second output terminal of the lithium niobate phase modulator. The second PI integrator and the frequency shift driver are both connected to the signal acquisition module.

[0016] In one or more embodiments of the present invention, the temperature control module includes a second analog-to-digital converter, a third signal demodulation device, a third PI integrator, a third digital-to-analog converter, and a TEC temperature control device connected in sequence. The second analog-to-digital converter is connected to the second photodetector, and the TEC temperature control device is connected to the resonant cavity.

[0017] In one or more embodiments of the present invention, the resonant cavity is selected from an optical fiber resonant cavity or a waveguide resonant cavity; the material of the optical fiber resonant cavity includes single-mode optical fiber, polarization-maintaining optical fiber, and photonic crystal optical fiber; the material of the waveguide resonant cavity includes silicon dioxide, silicon nitride, silicon, and polymers.

[0018] Compared with the prior art, the optical gyroscope system based on real-time temperature detection and control of the resonant cavity in the embodiments of the present invention can make the resonant cavity work at the optimal temperature point regardless of the material used for the resonant cavity, thereby maintaining the high precision of the optical gyroscope and achieving long-term working stability.

[0019] The optical gyroscope system based on real-time temperature detection and control of the resonant cavity in this invention demodulates the second harmonic signal. The peak value of the second harmonic demodulation curve is proportional to the intensity value of the resonant peak. When the temperature changes, due to polarization errors, the peak value of the resonant peak will change, and the demodulation value of the second harmonic will also change accordingly. This allows for real-time detection of the temperature change of the resonant cavity, which is then fed back to the TEC temperature control device via a PI integrator to adjust the operating temperature of the resonant cavity in a timely manner. This ensures that the resonant cavity always operates at the optimal temperature point, achieving long-term operational stability of the optical gyroscope.

[0020] The optical gyroscope system based on real-time temperature detection and control of the resonant cavity according to the embodiments of the present invention can be used for temperature control of resonant cavities made of any material. Compared with resonant cavities made of single polarization materials, which have higher costs, its structure is simpler and easier to implement, and it does not increase the cost of the original gyroscope system. Attached Figure Description

[0021] Figure 1 It shows the changes in the output resonance curve of the resonant cavity at different temperatures;

[0022] Figure 2 This is a schematic diagram of an optical gyroscope system based on real-time temperature detection and control of a resonant cavity according to an embodiment of the present invention. Detailed Implementation

[0023] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0024] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0025] As mentioned in the background section, the stability of the resonant cavity's operating temperature is crucial for the long-term operational stability of optical gyroscopes. For existing resonant optical gyroscope systems, due to the birefringence effect of the resonant cavity material, two polarization states are excited within the cavity, and these states are temperature-dependent. When the external temperature changes, the position of the resulting resonance curve changes, and polarization interference peaks and valleys are generated at a certain temperature. (Refer to...) Figure 1 As shown, (a) represents destructive interference between the primary and secondary resonance peaks, (b) represents no interference between the primary and secondary resonance peaks, and (c) represents dilatant interference between the primary and secondary resonance peaks. Through... Figure 1As can be seen, the resonance curve output from the transmission end of the waveguide resonant cavity simultaneously contains two polarization states, TE and TM. Furthermore, as the refractive index of the two polarization states changes, the phase difference between the two polarization states, TE and TM, also changes, i.e., it fluctuates between 0 and 2π. The positions of the two resonance curves will change significantly. Under a certain temperature environment, polarization interference peaks and valleys will be formed. This will seriously affect the temperature performance of the resonant optical gyroscope. The resonant curve output from the resonant cavity will deteriorate near the interference peaks and valleys, which will affect the detection accuracy of the resonant optical gyroscope.

[0026] In existing technologies, the above problems can be addressed using the following methods, but these methods all have significant limitations. First, optical gyroscopes based on fiber optic ring resonator structures can reduce polarization noise by fusion splicing the fiber axis by 90° rotation, adding a polarizer within the cavity, and using single-polarization fibers; however, in actual experiments, it has been found that this method cannot completely suppress polarization noise and is still affected by temperature. Second, for optical gyroscopes based on wave resonators, although this can be achieved by inserting a half-wave plate into the resonator, it undoubtedly increases the total loss of the resonator and reduces the theoretical sensitivity of the optical gyroscope. Another effective method for suppressing polarization noise is to make the resonator support only a single polarization state of light transmission, such as using a silicon nitride waveguide with extremely low aspect ratio polarization properties to fabricate the resonator. Although reports indicate that single polarization of the resonator has been achieved, its excessively high transmission loss limits the detection accuracy of the optical gyroscope. Therefore, existing measures cannot simultaneously meet the requirements of low resonator loss and single polarization.

[0027] To address this, this application provides an optical gyroscope system based on real-time temperature detection and control of the resonant cavity. By setting a temperature control module that forms a closed loop with the resonant cavity, the system can ensure that the resonant cavity operates at its optimal temperature point regardless of the material used. This minimizes polarization noise and maintains the high precision of the optical gyroscope while achieving long-term operational stability.

[0028] One embodiment of the present invention provides an optical gyroscope system based on real-time temperature detection and control of a resonant cavity, comprising a light source module, a modulation module, a resonant cavity, a frequency locking module, a drive control module, and a temperature control module. The light source module is connected to the modulation module; the modulation module is connected to the resonant cavity; the resonant cavity is connected to the frequency locking module, the drive control module, and the temperature control module respectively; the frequency locking module is also connected to the light source module; the drive control module is also connected to the modulation module; and the temperature control module is connected to the resonant cavity.

[0029] The light beam emitted by the light source module is split into two paths in the modulation module. The first path of the light beam is output to the frequency locking module via the resonant cavity. The frequency locking module feeds back the information of the first path of the light beam to the light source module to control the center frequency of the light beam emitted by the light source module and locks this frequency to the resonant frequency of the resonant cavity. The second path of the light beam is output to the temperature control module via the resonant cavity. The temperature control module controls the temperature of the resonant cavity based on the information of the second path of the light beam. The second path of the light beam is also output to the drive control module via the resonant cavity. The drive control module controls the modulation module to shift the frequency of the light beam emitted by the light source module based on the information of the second path of the light beam.

[0030] In this embodiment, the optical gyroscope system based on real-time temperature detection and control of the resonant cavity further includes a signal acquisition module, a coupling module, and a detection module. The coupling module includes a first coupler and a second coupler; the detection module includes a first photodetector and a second photodetector. The signal acquisition module is connected to the drive control module to acquire a first frequency of the second beam that has not passed through the resonant cavity and a second frequency of the second beam that has passed through the resonant cavity. The signal acquisition module obtains the angular velocity information of the gyroscope system by acquiring the frequency difference signal between the first frequency and the second frequency. The modulation module is connected to the resonant cavity through the first coupler, and the resonant cavity is connected to the frequency locking module, the drive control module, and the temperature control module through the second coupler. The second coupler is connected to the frequency locking module through the first photodetector, and the second coupler is connected to the drive control module and the temperature control module through the second photodetector.

[0031] For example, the light source module includes a fiber laser and an optical isolator, with the output end of the fiber laser connected to the input end of the optical isolator.

[0032] For example, the modulation module includes a lithium niobate phase modulator, the first input terminal and the second input terminal of the lithium niobate phase modulator are both connected to the output terminal of the optical isolator, and the first output terminal and the second output terminal of the lithium niobate phase modulator are both connected to the input terminal of the first coupler.

[0033] For example, the frequency locking module includes a first analog-to-digital converter, a first signal demodulation device, a first PI integrator, and a first digital-to-analog converter connected in sequence. The first analog-to-digital converter is connected to the first photodetector, and the first digital-to-analog converter is connected to the fiber laser.

[0034] For example, the drive control module includes a second analog-to-digital converter, a second signal demodulation device, a second PI integrator, a frequency shift driver, and a second digital-to-analog converter connected in sequence. The second analog-to-digital converter is connected to the second photodetector, and the second digital-to-analog converter is connected to the second output terminal of the lithium niobate phase modulator. The second PI integrator and the frequency shift driver are both connected to the signal acquisition module.

[0035] For example, the temperature control module includes a second analog-to-digital converter, a third signal demodulation device, a third PI integrator, a third digital-to-analog converter, and a TEC temperature control device connected in sequence. The second analog-to-digital converter is connected to the second photodetector, and the TEC temperature control device is connected to the resonant cavity.

[0036] The second analog-to-digital converter in the drive control module and the second analog-to-digital converter in the temperature control module can be combined into a single analog-to-digital converter, or two separate analog-to-digital converters can be used.

[0037] For example, the resonant cavity is selected from fiber optic resonant cavities or waveguide resonant cavities; the material of the fiber optic resonant cavity includes single-mode fiber, polarization-maintaining fiber, and photonic crystal fiber; the material of the waveguide resonant cavity includes silicon dioxide, silicon nitride, silicon, and polymers.

[0038] The optical gyroscope system based on real-time temperature detection and control of the resonant cavity of the present invention is described in detail below through a specific embodiment.

[0039] refer to Figure 2 As shown, this embodiment provides an optical gyroscope system based on real-time temperature detection and control of a resonant cavity, including: a fiber laser 11, an optical isolator 12, a lithium niobate phase modulator 2, a first coupler 31, a resonant cavity 4, a second coupler 32, a first photodetector 51, a second photodetector 52, a first analog-to-digital converter 61, a first signal demodulation device 62, a first PI integrator 63, a first digital-to-analog converter 64, a second analog-to-digital converter 71 / 91, a second signal demodulation device 72, a second PI integrator 73, a frequency shift driver 74, a second digital-to-analog converter 75, a signal acquisition device 8, a third signal demodulation device 92, a third PI integrator 93, a third digital-to-analog converter 94, and a TEC temperature control device 95. The fiber laser 11 is preferably a narrow-linewidth fiber laser; the lithium niobate phase modulator 2 has a first input terminal 2a, a second input terminal 2c, a first output terminal 2b, and a second output terminal 2d.

[0040] The output of fiber laser 11 is connected to the input of optical isolator 12, and the output of optical isolator 12 is connected to the first input 2a and the second input 2c of lithium niobate phase modulator 2. Lithium niobate phase modulator 2 consists of upper and lower modulation arms. The upper modulation arm has a first input 2a and a first output 2b, and the lower modulation arm has a second input 2c and a second output 2d. The first output 2b of the upper modulation arm of lithium niobate phase modulator 2 is connected to the input of first coupler 31, which is connected to resonant cavity 4. The coupling output of resonant cavity 4... The output of the second coupler 32 is connected to the input of the first photodetector 51. The output of the first photodetector 51 is connected to the input of the first analog-to-digital converter 61 via a coaxial cable. The output of the first analog-to-digital converter 61 is connected to the input of the first signal demodulation device 62. The output of the first signal demodulation device 62 is connected to the input of the first PI integrator 63. The output of the first PI integrator 63 is connected to the input of the first digital-to-analog converter 64. The output of the first digital-to-analog converter 64 is connected to the fiber laser 11.

[0041] Furthermore, the second output terminal 2d of the lower modulation arm of the lithium niobate phase modulator 2 is connected to the other input terminal of the first coupler 31, the coupling output terminal of the resonant cavity 4 is connected to the other input terminal of the second coupler 32, the output terminal of the second coupler 32 is connected to the input terminal of the second photodetector 52, the output terminal of the second photodetector 52 is connected to the input terminal of the second analog-to-digital converter 71 / 91 via a coaxial cable, the output terminal of the second analog-to-digital converter 71 / 91 is connected to the input terminal of the second signal demodulation device 72, the output terminal of the second signal demodulation device 72 is connected to the input terminal of the second PI integrator 73, the output terminal of the second PI integrator 73 is connected to the input terminal of the frequency shift driver 74 and the input terminal of the signal acquisition device 8, respectively, the output terminal of the frequency shift driver 74 is connected to the input terminal of the second digital-to-analog converter 75, and the output terminal of the second digital-to-analog converter 75 is connected to the second output terminal 2d of the lower modulation arm of the lithium niobate phase modulator 2.

[0042] Furthermore, another output terminal of the second analog-to-digital converter 71 / 91 is connected to the input terminal of the third signal demodulation device 92, the output terminal of the third signal demodulation device 92 is connected to the input terminal of the third PI integrator 93, the output terminal of the third PI integrator 93 is connected to the input terminal of the third digital-to-analog converter 94, and the output terminal of the third digital-to-analog converter 94 is connected to the input terminal of the TEC temperature control device 95.

[0043] The specific working process of the optical gyroscope system based on real-time temperature detection and control of the resonant cavity of the present invention is as follows:

[0044] a. The light output from the fiber laser 11 first passes through the optical isolator 12, then enters the lithium niobate phase modulator 2 to polarize and split the light source. Sine or triangular wave modulation signals of different frequencies are then applied to the first input terminal 2a and the second input terminal 2c of the lithium niobate phase modulator 2 to modulate the light source. To further suppress backscatter noise, a low-frequency triangular wave carrier signal is applied to both beams at the first output terminal 2b and the second output terminal 2d of the lithium niobate phase modulator 2 to suppress the carrier amplitude. The modulated light source enters the resonant cavity 4 from the two input terminals of the first coupler 31, and is then coupled out from the two output terminals of the second coupler 32.

[0045] b. The light input in the counterclockwise direction (i.e., the first beam) is coupled out from the second coupler 32 and enters the first photodetector 51 for photoelectric conversion. Then, it is output into the first digital-to-analog converter 61 to convert the analog signal into a digital signal. After the output, it passes through the first signal demodulation device 62 to demodulate the modulated signal. Then, it passes through the first PI integrator 63 for control output. Then, it passes through the first digital-to-analog converter 64 to convert the digital signal into an analog signal. This signal is input to the fiber laser 11 to control the center frequency of the fiber laser 11 and lock it at the resonant frequency of the resonant cavity 4, forming the first closed loop.

[0046] c. The light input in a clockwise direction (i.e., the second beam) is coupled out from the second coupler 32 and enters the second photodetector 52 for photoelectric conversion. Then, the output enters the second digital-to-analog converter 71 / 91 to convert the analog signal into a digital signal. After the output, it first passes through the second signal demodulation device 72 to demodulate the modulated signal. Then, the output passes through the second PI integrator 73 for control. After the output of the second PI integrator 73, the signal is fed back to the frequency shift driver 74. When there is a rotation signal in the gyroscope system, the frequency shift driver 74 will generate a sawtooth wave signal of a certain frequency. After the sawtooth wave signal is converted from digital to analog by the second digital-to-analog converter 75, it is applied to the second output terminal 2d of the lithium niobate phase modulator 2 to realize the frequency shift of the laser source. This allows the light source frequency (second beam) input in the clockwise direction in the resonant cavity 4 to also track and lock, forming a second closed loop. The gyroscope testing system reflects the gyroscope's angular velocity information by reading the frequency difference signal of two beams (i.e., the second beam that does not pass through the resonant cavity 4 and the second beam that passes through the resonant cavity 4), which is acquired by the signal acquisition device 8.

[0047] d. The light output from the second photodetector 52 enters the second analog-to-digital converter 71 / 91 for analog-to-digital conversion, and then enters the third signal demodulation device 92 from its other output terminal to demodulate the modulated signal by frequency doubling. The output then passes through the third PI integrator 93 for feedback control. After output, the signal is converted from digital to analog by the third digital-to-analog converter 94 and then fed back to the TEC temperature control device 95 to control the temperature of the resonant cavity 4.

[0048] e. The TEC temperature control device 95 performs second-harmonic demodulation on the clockwise path (i.e., the second beam). Since the intensity of the second-harmonic demodulation curve is proportional to the cavity resonance curve, the position of the resonance curve changes with temperature. When the temperature change is large, the intensity of the resonance peak changes due to polarization error, and the second-harmonic demodulation value also changes significantly. The second-harmonic demodulation value is fed back to the TEC control terminal of the TEC temperature control device 95 in the resonant cavity 4 through the third PI integrator 93. By judging the magnitude of the second-harmonic demodulation value, the temperature of the resonant cavity 4 can be adjusted in real time, ensuring that the resonant cavity 4 always operates in a stable temperature environment, improving the stability of the resonant cavity 4's operating environment, and achieving the goal of long-term operational stability of the optical gyroscope.

[0049] Compared with the prior art, the optical gyroscope system based on real-time temperature detection and control of the resonant cavity in the embodiments of the present invention can make the resonant cavity work at the optimal temperature point regardless of the material used for the resonant cavity, thereby maintaining the high precision of the optical gyroscope and achieving long-term working stability.

[0050] The optical gyroscope system based on real-time temperature detection and control of the resonant cavity in this invention demodulates the second harmonic signal. The peak value of the second harmonic demodulation curve is proportional to the intensity value of the resonant peak. When the temperature changes, due to polarization errors, the peak value of the resonant peak will change, and the demodulation value of the second harmonic will also change accordingly. This allows for real-time detection of the temperature change of the resonant cavity, which is then fed back to the TEC temperature control device via a PI integrator to adjust the operating temperature of the resonant cavity in a timely manner. This ensures that the resonant cavity always operates at the optimal temperature point, achieving long-term operational stability of the optical gyroscope.

[0051] The optical gyroscope system based on real-time temperature detection and control of the resonant cavity according to the embodiments of the present invention can be used for temperature control of resonant cavities made of any material. Compared with resonant cavities made of single polarization materials, which have higher costs, its structure is simpler and easier to implement, and it does not increase the cost of the original gyroscope system.

[0052] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An optical gyroscope system based on real-time temperature detection and control of a resonant cavity, characterized in that, include: The light source module, modulation module, resonant cavity, frequency locking module, drive control module, and temperature control module; The light source module is connected to the modulation module; The modulation module is connected to the resonant cavity; the resonant cavity is connected to the frequency locking module, the drive control module, and the temperature control module respectively; the frequency locking module is also connected to the light source module; the drive control module is also connected to the modulation module. The light beam emitted by the light source module is split into two paths in the modulation module. The first path of the light beam is output to the frequency locking module via the resonant cavity. The frequency locking module feeds back the information of the first path of the light beam to the light source module to control the center frequency of the light beam emitted by the light source module and locks this frequency to the resonant frequency of the resonant cavity. The second path of the light beam is output to the temperature control module via the resonant cavity. The temperature control module controls the temperature of the resonant cavity based on the information of the second path of the light beam. The second path of the light beam is also output to the drive control module via the resonant cavity. The drive control module controls the modulation module to shift the frequency of the light beam emitted by the light source module based on the information of the second path of the light beam. The temperature control module includes a third signal demodulation device, a third PI integrator, and a TEC temperature control device. The third signal demodulation device is used to demodulate the second harmonic signal of the second beam and feed the demodulated value back to the TEC temperature control device through the third PI integrator to adjust the temperature of the resonant cavity in real time.

2. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 1, characterized in that, The system also includes a signal acquisition module connected to the drive control module to acquire the first frequency of the second beam that has not passed through the resonant cavity and the second frequency of the second beam that has passed through the resonant cavity. The signal acquisition module acquires the angular velocity information of the gyroscope system by obtaining the frequency difference signal between the first frequency and the second frequency.

3. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 2, characterized in that, The system further includes a coupling module, which includes a first coupler and a second coupler. The modulation module is connected to the resonant cavity through the first coupler, and the resonant cavity is connected to the frequency locking module, the drive control module, and the temperature control module through the second coupler.

4. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 3, characterized in that, The system also includes a detection module, which includes a first photodetector and a second photodetector. The second coupler is connected to the frequency locking module through the first photodetector, and the second coupler is connected to the drive control module and the temperature control module through the second photodetector.

5. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 4, characterized in that, The light source module includes a fiber laser and an optical isolator, with the output end of the fiber laser connected to the input end of the optical isolator.

6. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 5, characterized in that, The modulation module includes a lithium niobate phase modulator, the first and second input terminals of which are both connected to the output terminal of the optical isolator, and the first and second output terminals of which are both connected to the input terminal of the first coupler.

7. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 6, characterized in that, The frequency locking module includes a first analog-to-digital converter, a first signal demodulation device, a first PI integrator, and a first digital-to-analog converter connected in sequence. The first analog-to-digital converter is connected to the first photodetector, and the first digital-to-analog converter is connected to the fiber laser.

8. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 6, characterized in that, The drive control module includes a second analog-to-digital converter, a second signal demodulation device, a second PI integrator, a frequency shift driver, and a second digital-to-analog converter connected in sequence. The second analog-to-digital converter is connected to the second photodetector, and the second digital-to-analog converter is connected to the second output terminal of the lithium niobate phase modulator. The second PI integrator and the frequency shift driver are both connected to the signal acquisition module.

9. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 4, characterized in that, The temperature control module further includes a second analog-to-digital converter and a third digital-to-analog converter. The second analog-to-digital converter, the third signal demodulation device, the third PI integrator, the third digital-to-analog converter, and the TEC temperature control device are connected in sequence. The second analog-to-digital converter is connected to the second photodetector, and the TEC temperature control device is connected to the resonant cavity.

10. The optical gyroscope system based on real-time temperature detection and control of a resonant cavity as described in claim 1, characterized in that, The resonant cavity is selected from fiber optic resonant cavities or waveguide resonant cavities; the fiber optic resonant cavity is made of materials including single-mode fiber, polarization-maintaining fiber, and photonic crystal fiber; the waveguide resonant cavity is made of materials including silicon dioxide, silicon nitride, silicon, and polymers.

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