CN108168537A - The detecting system and method for resonance type optical gyroscope based on quadrature demodulation - Google Patents

Abstract

The invention discloses a detection system and method of a resonant optical gyroscope based on quadrature demodulation. The present invention first performs phase modulation on the laser input to the optical ring resonator, and performs synchronous quadrature demodulation on the clockwise and counterclockwise output signals out of the cavity, wherein one quadrature demodulation signal is processed as an error signal through The servo loop controls the frequency of the laser, so that the output optical frequency of the laser is tracked and locked on this resonant frequency; the other quadrature demodulation signal is processed and output as a gyro signal. The detection method of the resonant optical gyroscope provided by the invention is beneficial to automatically adjust and demodulate the phase to the point of maximum sensitivity; the phase noise of devices in the system loop is suppressed, and the signal-to-noise ratio of the system is improved.

Description

Detection system and method of resonant optical gyroscope based on quadrature demodulation

technical field

The invention relates to the technical field of signal detection, in particular to a detection system and method of a resonant optical gyro with quadrature demodulation. Resonant gyroscopes include resonant fiber optic gyroscopes with optical fiber ring resonators as sensitive components and resonant integrated optical gyroscopes with optical waveguide resonant cavities as core sensitive components.

Background technique

Resonator Optic Gyro (ROG) is a high-precision miniature inertial sensor that uses the optical Sagnac effect to detect rotation. The resonant optical gyro without vibrating parts has the advantages of miniaturization, high precision and anti-vibration. Compared with Micro Electro Mechanical Systems (MEMS) and Interferometric Fiber Optical Gyroscope (IFOG), ROG will have greater advantages.

Because the Sagnac effect is a very weak effect, and the optical noise of the resonant optical gyroscope is very strong, so in the resonant optical gyroscope system, signal modulation and detection and noise suppression technology occupy a very important position. When the system signal is demodulated, it is necessary to manually adjust the phase to maximize the sensitivity of the system, which is not conducive to the industrial production of the gyro system. And there is phase noise in the instruments in the system, which will affect the output of the gyroscope.

Contents of the invention

The object of the present invention is to provide a resonant optical gyro detection system and method based on quadrature demodulation to address the shortcomings of the prior art.

The purpose of the present invention is achieved by the following technical solutions:

A detection system for a resonant optical gyro based on quadrature demodulation, which includes a tunable laser, an optical isolator, an optical splitter, a first phase modulator, a second phase modulator, an optical resonant cavity, and a photoelectric conversion module The formed optical system and the signal processing system composed of signal modulation and demodulation module, feedback locking module, first signal processing module and second signal processing module;

The tunable laser, the optical isolator and the optical splitter are connected in sequence, the optical splitter is respectively connected with the first phase modulator and the second phase modulator, the first phase modulator is connected with the optical resonant cavity, and the second phase modulator It is connected with the optical resonant cavity, the optical resonant cavity, the photoelectric conversion module and the signal modulation and demodulation module are connected in turn, the signal modulation and demodulation module is connected with the first phase modulation module, the signal modulation and demodulation module is connected with the second phase modulation module, and the signal modulation and demodulation module is connected with the second phase modulation module. The demodulation module, the first signal processing module, and the feedback locking module are sequentially connected to the tunable laser, and the signal modulation and demodulation module is connected to the second signal processing module.

The detection method of the above-mentioned detection system comprises the following steps:

(1) Phase modulation: After the laser light emitted by the tunable laser passes through the optical isolator, it is divided into two beams with the same power by the optical splitter, and then modulated by the first phase modulator and the second phase modulator respectively, specifically : The signal modulation and demodulation module generates carrier-suppressed modulation signals U ₁ (t) and U ₂ (t) to respectively drive the first phase modulator and the second phase modulator to complete the phase modulation, thus completing the inverse of entering the optical resonator Phase modulation and carrier suppression for clockwise and clockwise light;

(2) Orthogonal demodulation of signals: Two beams of light after phase modulation are input into the optical resonant cavity to form two resonant beams counterclockwise and clockwise. These two beams of light enter the photodetector respectively and convert them into electrical signals. The demodulation module generates orthogonal signals of the same frequency to demodulate the electrical signals converted by the clockwise beam respectively, and generates demodulated signals U ₃ (t) and U ₄ (t); the signal modulation and demodulation module generates orthogonal signals of the same frequency Demodulate the electrical signals converted from the counterclockwise light beams respectively to generate demodulated signals U ₅ (t) and U ₆ (t);

(3) Signal processing of the quadrature demodulation signal: in the second signal processing module, the two quadrature demodulation signals U ₃ (t) and U ₄ (t) in the clockwise direction are respectively squared and added, and then The square root sign is used to obtain the non-negative even function signal U ₇ (t), and U ₇ (t) is reversed according to the positive or negative of one of the quadrature demodulation signals (it can be judged according to the parameter setting of the system, such as U ₃ (t) is positive, let U ₇ (t) be positive, U ₃ (t) is negative, let U ₇ (t) be negative), and finally get the odd function signal U ₈ (t); in the first signal In the processing module, the two quadrature demodulation signals U ₅ (t) and U ₆ (t) in the counterclockwise direction are squared and added together, and then the root sign is obtained to obtain the non-negative even function signal U ₉ (t), according to One of the quadrature demodulation signals is used to flip U ₉ (t) (it can be judged according to the parameter setting of the system, such as U ₅ (t) is positive, let U ₉ (t) be positive, When U ₅ (t) is negative, make U ₉ (t) negative), and finally get an odd function signal U ₁₀ (t);

(4) Gyro signal output: the counterclockwise signal is processed by the first signal processing module and transmitted to the feedback locking module as an error signal, and the feedback locking module performs proportional and integral calculations on it and feedback controls the tunable laser; clockwise After the signal is processed by the second signal processing module, it is output to the data recorder as a resonant optical gyro signal.

A detection system based on a quadrature demodulation resonant optical gyroscope, characterized in that it includes a tunable laser, an optical isolator, an optical splitter, a first phase modulator, a second phase modulator, a third phase An optical system composed of a modulator, an optical resonant cavity, and a photoelectric conversion module, and a signal processing system composed of a signal modulation and demodulation module, a feedback locking module, a first signal processing module, a second signal processing module, and a servo frequency shift module;

The tunable laser, the optical isolator and the optical splitter are connected in sequence, the optical splitter is connected to the first phase modulator and the second phase modulator respectively, and the first phase modulator, the third phase modulator and the optical resonant cavity are connected in sequence The second phase modulator is connected to the optical resonant cavity, the optical resonant cavity, the photoelectric conversion module are connected to the signal modulation and demodulation module in sequence, the signal modulation and demodulation module is connected to the first phase modulator, and the signal modulation and demodulation module is connected to the second The phase modulators are connected, the signal modulation and demodulation module, the first signal processing module, the feedback locking module and the tunable laser are connected in sequence, the signal modulation and demodulation module, the second signal processing module, the servo frequency shift module and the third phase modulator are sequentially connected connected.

The detection method of the above-mentioned detection system comprises the following steps:

(1) Phase modulation: After the laser light emitted by the tunable laser passes through the optical isolator, it is divided into two beams with the same power by the optical splitter, and then modulated by the first phase modulator and the second phase modulator respectively, specifically : The signal modulation and demodulation module generates carrier-suppressed modulation signals U ₁ (t) and U ₂ (t) to respectively drive the first phase modulator and the second phase modulator to complete the phase modulation, thus completing the inverse of entering the optical resonator Phase modulation and carrier suppression for clockwise and clockwise light;

(2) Orthogonal demodulation of signals: two beams of light after phase modulation are input into the optical resonant cavity to form two resonant beams counterclockwise and clockwise. These two beams of light enter the photodetector respectively and convert them into electrical signals; signal modulation The demodulation module generates orthogonal signals of the same frequency to demodulate the electrical signals converted by the clockwise beam respectively, and generates demodulated signals U ₃ (t) and U ₄ (t); the signal modulation and demodulation module generates orthogonal signals of the same frequency Demodulate the electrical signals converted from the counterclockwise light beams respectively to generate demodulated signals U ₅ (t) and U ₆ (t);

(3) Signal processing of the quadrature demodulation signal: in the second signal processing module, the two quadrature demodulation signals U ₃ (t) and U ₄ (t) in the clockwise direction are respectively squared and added, and then The square root sign is used to obtain the non-negative even function signal U ₇ (t), and U ₇ (t) is reversed according to the positive or negative of one of the quadrature demodulation signals (it can be judged according to the parameter setting of the system, such as U ₃ (t) is positive, let U ₇ (t) be positive, U ₃ (t) is negative, let U ₇ (t) be negative), and finally get the odd function signal U ₈ (t); in the first signal In the processing module, the two quadrature demodulation signals U ₅ (t) and U ₆ (t) in the counterclockwise direction are squared and added together, and then the root sign is obtained to obtain the non-negative even function signal U ₉ (t), according to One of the quadrature demodulation signals is used to flip U ₉ (t) (it can be judged according to the parameter setting of the system, such as U ₅ (t) is positive, let U ₉ (t) be positive, When U ₅ (t) is negative, make U ₉ (t) negative), and finally get an odd function signal U ₁₀ (t).

(4) Gyro signal output: the counterclockwise signal is transmitted to the feedback locking module as an error signal after passing through the first signal processing module, and the feedback locking module performs proportional and integral calculations on it, and feedback controls the tunable laser, and the clockwise signal , after passing through the second signal processing module, it is transmitted to the servo frequency shifting module, and finally acts on the third phase modulator, so that the clockwise path also works at the resonant frequency point, and the frequency shifting amount is the rotation output signal of the gyroscope.

The beneficial effect that the present invention has:

1. The detection method of the resonant optical gyroscope provided by the present invention is beneficial to automatically adjust the demodulation phase to the maximum sensitivity point.

2. The detection method of the resonant optical gyroscope provided by the present invention suppresses the phase noise of the system components of the resonant optical gyroscope, and improves the signal-to-noise ratio of the system.

3. The detection method of the resonant optical gyroscope provided by the present invention can suppress the backscatter noise while suppressing the phase noise, thereby improving the stability of the system.

Description of drawings

FIG. 1 is a schematic structural diagram of the first quadrature demodulation resonant optical gyroscope detection system of the present invention.

FIG. 2 is a schematic structural diagram of a second quadrature demodulation resonant optical gyroscope detection system of the present invention.

Fig. 3 is a schematic diagram of a curve outputted by quadrature demodulation after signal processing.

Fig. 4 is a schematic diagram of the relationship between clockwise and counterclockwise resonant frequency and laser frequency when the resonant optical gyroscope rotates.

Fig. 5 is a schematic diagram of a specific implementation case of a detection system based on a quadrature demodulation resonant optical gyroscope.

In the figure: 1. Tunable laser, 2. Isolator, 3. Optical splitter, 4. First phase modulator, 5. Second phase modulator, 6. First circulator, 7. Second circulator, 8. Optical resonant cavity, 9. First photodetector, 10. Second photodetector, 11. Signal modulation and demodulation module, 12. First signal processing module, 13. Feedback locking module, 14. Second signal processing Module, 15. Data recorder.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments and accompanying drawings, but the present invention is not limited thereto.

As shown in Figure 1, a resonant optical gyro detection system based on quadrature demodulation is characterized in that it includes a tunable laser, an optical isolator, an optical splitter, a first phase modulator, a second phase An optical system composed of a modulator, an optical resonant cavity, and a photoelectric conversion module, and a signal processing system composed of a signal modulation and demodulation module, a feedback locking module, a first signal processing module, and a second signal processing module;

The tunable laser, the optical isolator and the optical splitter are connected in sequence, the optical splitter is respectively connected with the first phase modulator and the second phase modulator, the first phase modulator is connected with the optical resonant cavity, and the second phase modulator It is connected with the optical resonant cavity, the optical resonant cavity, the photoelectric conversion module and the signal modulation and demodulation module are connected in turn, the signal modulation and demodulation module is connected with the first phase modulation module, the signal modulation and demodulation module is connected with the second phase modulation module, and the signal modulation and demodulation module is connected with the second phase modulation module. The demodulation module, the first signal processing module, and the feedback locking module are sequentially connected to the tunable laser, and the signal modulation and demodulation module is connected to the second signal processing module.

The detection method of the above-mentioned detection system comprises the following steps:

(1) Phase modulation: After the laser light emitted by the tunable laser passes through the optical isolator, it is divided into two beams with the same power by the optical splitter, and then modulated by the first phase modulator and the second phase modulator respectively, specifically : The signal modulation and demodulation module generates carrier-suppressed modulation signals U ₁ (t) and U ₂ (t) to respectively drive the first phase modulator and the second phase modulator to complete the phase modulation, thus completing the inverse of entering the optical resonator Phase modulation and carrier suppression for clockwise and clockwise light;

(2) Orthogonal demodulation of signals: Two beams of light after phase modulation are input into the optical resonant cavity to form two resonant beams counterclockwise and clockwise. These two beams of light enter the photodetector respectively and convert them into electrical signals. The demodulation module generates orthogonal signals of the same frequency to demodulate the electrical signals converted by the clockwise beam respectively, and generates demodulated signals U ₃ (t) and U ₄ (t); the signal modulation and demodulation module generates orthogonal signals of the same frequency Demodulate the electrical signals converted from the counterclockwise light beams respectively to generate demodulated signals U ₅ (t) and U ₆ (t);

(3) Signal processing of the quadrature demodulation signal: in the second signal processing module, the two quadrature demodulation signals U ₃ (t) and U ₄ (t) in the clockwise direction are respectively squared and added, and then The square root sign is used to obtain the non-negative even function signal U ₇ (t), and U ₇ (t) is reversed according to the positive or negative of one of the orthogonal demodulation signals (it can be judged according to the parameter setting of the system, as in this implementation In the example, when U ₃ (t) is positive, let U ₇ (t) be positive, and when U ₃ (t) is negative, let U ₇ (t) be negative), and finally get the odd function signal U ₈ (t) ; In the first signal processing module, the two quadrature demodulation signals U ₅ (t) and U ₆ (t) in the counterclockwise direction are respectively squared and added, and then the root sign is obtained to obtain the non-negative even function signal U ₉ (t), U ₉ (t) is reversed according to the positive or negative of one of the quadrature demodulation signals, (it can be judged according to the parameter setting of the system, as in this embodiment, U ₅ (t) is positive When U ₉ (t) is positive, when U ₅ (t) is negative, U ₉ (t) is negative), and finally the odd function signal U ₁₀ (t) is obtained;

(4) Gyro signal output: the counterclockwise signal is processed by the first signal processing module and transmitted to the feedback locking module as an error signal, and the feedback locking module performs proportional and integral calculations on it and feedback controls the tunable laser; clockwise After the signal is processed by the second signal processing module, it is output to the data recorder as a resonant optical gyro signal.

As shown in Figure 2, a resonant optical gyro detection system based on quadrature demodulation is characterized in that it includes a tunable laser, an optical isolator, an optical splitter, a first phase modulator, a second phase The optical system composed of the modulator, the third phase modulator, the optical resonant cavity, and the photoelectric conversion module, and the signal modulation and demodulation module, the feedback locking module, the first signal processing module, the second signal processing module, and the servo frequency shifting module signal processing system;

The tunable laser, the optical isolator and the optical splitter are connected in sequence, the optical splitter is connected to the first phase modulator and the second phase modulator respectively, and the first phase modulator, the third phase modulator and the optical resonant cavity are connected in sequence The second phase modulator is connected to the optical resonant cavity, the optical resonant cavity, the photoelectric conversion module are connected to the signal modulation and demodulation module in sequence, the signal modulation and demodulation module is connected to the first phase modulator, and the signal modulation and demodulation module is connected to the second The phase modulators are connected, the signal modulation and demodulation module, the first signal processing module, the feedback locking module and the tunable laser are connected in sequence, the signal modulation and demodulation module, the second signal processing module, the servo frequency shift module and the third phase modulator are sequentially connected connected.

The detection method of the above-mentioned detection system comprises the following steps:

(1) Phase modulation: After the laser light emitted by the tunable laser passes through the optical isolator, it is divided into two beams with the same power by the optical splitter, and then modulated by the first phase modulator and the second phase modulator respectively, specifically : The signal modulation and demodulation module generates carrier-suppressed modulation signals U ₁ (t) and U ₂ (t) to respectively drive the first phase modulator and the second phase modulator to complete the phase modulation, thus completing the inverse of entering the optical resonator Phase modulation and carrier suppression for clockwise and clockwise light;

(2) Orthogonal demodulation of signals: two beams of light after phase modulation are input into the optical resonant cavity to form two resonant beams counterclockwise and clockwise. These two beams of light enter the photodetector respectively and convert them into electrical signals; signal modulation The demodulation module generates orthogonal signals of the same frequency to demodulate the electrical signals converted by the clockwise beam respectively, and generates demodulated signals U ₃ (t) and U ₄ (t); the signal modulation and demodulation module generates orthogonal signals of the same frequency Demodulate the electrical signals converted from the counterclockwise light beams respectively to generate demodulated signals U ₅ (t) and U ₆ (t);

(3) Signal processing of the quadrature demodulation signal: in the second signal processing module, the two quadrature demodulation signals U ₃ (t) and U ₄ (t) in the clockwise direction are respectively squared and added, and then The square root sign is used to obtain the non-negative even function signal U ₇ (t), and U ₇ (t) is reversed according to the positive or negative of one of the quadrature demodulated signals (it can be judged according to the parameter setting of the system, as in this implementation In the example, when U ₃ (t) is positive, let U ₇ (t) be positive, and when U ₃ (t) is negative, let U ₇ (t) be negative), and finally get the odd function signal U ₈ (t ); in the first signal processing module, the two quadrature demodulation signals U ₅ (t) and U ₆ (t) in the counterclockwise direction are respectively squared and added, and then the root sign is obtained to obtain the non-negative even function signal U ₉ (t), flip U ₉ (t) according to the positive or negative of one of the orthogonal demodulation signals (it can be judged according to the parameter setting of the system, as in this embodiment, U ₅ (t) is positive When U ₉ (t) is positive, when U ₅ (t) is negative, U ₉ (t) is negative), and finally an odd function signal U ₁₀ (t) is obtained.

(4) Gyro signal output: the counterclockwise signal is transmitted to the feedback locking module as an error signal after passing through the first signal processing module, and the feedback locking module performs proportional and integral calculations on it, and feedback controls the tunable laser, and the clockwise signal , after passing through the second signal processing module, it is transmitted to the servo frequency shifting module, and finally acts on the third phase modulator, so that the clockwise path also works at the resonant frequency point, and the frequency shifting amount is the rotation output signal of the gyroscope.

As shown in Figure 3, the output demodulation curve of the resonant optical gyroscope based on quadrature demodulation is given. The demodulation curve reflects the relationship between the resonance frequency difference and the demodulation amplitude. The middle linear region is the working range of the gyro. When the gyro rotates, there will be a difference in resonant frequency, and the demodulation value will not be 0. Through the calibration coefficient, the rotational angular velocity of the gyroscope can be calculated.

As shown in Figure 4, a schematic diagram of the relationship between the clockwise and counterclockwise resonant frequencies and the laser frequency when the resonant optical gyroscope rotates is given. The frequency of the laser is always stable at the resonant frequency of the counterclockwise beam, and the difference between the resonant frequency of the clockwise and counterclockwise beams is the rotation signal of the resonant optical gyroscope.

As shown in Figure 5, it is a real-time case of a resonant optical gyroscope based on quadrature demodulation. The present invention uses a semiconductor tunable laser as a tunable laser, Y branch as an optical splitter, and an optical phase modulator as a modulator , the photodetector is used as the photoelectric conversion module, and the code is written on the FPGA-based development platform to realize the signal modulation and demodulation module, the signal processing module, the feedback locking module, and the digital multimeter or personal computer is used as the data recorder.

Claims (8)

1. a kind of detecting system of the resonance type optical gyroscope based on quadrature demodulation, which is characterized in that it includes tunable laser Device, optical isolator, optical splitters, first phase modulator, second phase modulator, optical resonator, opto-electronic conversion mould The optical system and believed by the modulation /demodulation module of signal, feedback lock module, the first signal processing module, second that block is formed The signal processing system that number processing module is formed；

Tunable laser, optical isolator and optical splitters are sequentially connected, and optical splitters are modulated respectively with first phase Device, second phase modulator are connected, and first phase modulator is connected with optical resonator, second phase modulator and optical resonance Chamber is connected, and optical resonator, photoelectric conversion module and modulating and demodulating signal module are sequentially connected, modulating and demodulating signal module and the One phase modulation module is connected, and modulating and demodulating signal module is connected with second phase modulation module, modulating and demodulating signal module, One signal processing module, feedback lock module and tunable laser are sequentially connected, modulating and demodulating signal module and second signal Processing module is connected.

2. the detecting system of the resonance type optical gyroscope based on quadrature demodulation as described in claim 1, it is characterised in that described Optical resonator be optical fibre device or integrated optical device.

3. the detecting system of the resonance type optical gyroscope based on quadrature demodulation as claimed in claim 1 or 2, it is characterised in that institute The structure for the optical resonator stated is transmitted light resonator or reflective optic resonator.

4. a kind of detection method using detecting system described in claim 1, which is characterized in that include the following steps：

(1) phase-modulation：The laser sent out by tunable laser is divided into work(after optical isolator, by optical splitters Two identical beams of rate, then respectively by first phase modulator and second phase modulators modulate, specifically：Signal modulation solution Mode transfer block generates carrier suppressed modulation signal U₁(t) and U₂(t) it respectively drives first phase modulator and second phase modulator is complete Into phase-modulation, phase-modulation and carrier wave this completes the light counterclockwise and clockwise to entering optical resonator press down System；

(2) quadrature demodulation of signal：By the two-beam of phase-modulation, optical resonator is inputted, is formed counterclockwise and clockwise Two resonance light beams, this two-beam respectively enters photodetector and is converted into electric signal, and modulating and demodulating signal module generates same The electric signal that frequency orthogonal signalling are respectively converted into light beam clockwise is demodulated, and generates demodulated signal U₃(t) and U₄(t)；Signal The electric signal that the generation of modulation /demodulation module is respectively converted into light beam counterclockwise with frequency orthogonal signalling is demodulated, and generates demodulation letter Number U₅(t) and U₆(t)；

(3) signal processing of quadrature demodulated signal：In second signal processing module, clockwise two-way quadrature demodulation letter Number U₃(t) and U₄(t), respectively square after be added, then open radical sign and obtain non-negative even function signal U₇(t), according to it is therein all the way The positive negativity of quadrature demodulated signal is come to U₇(t) it is overturn, finally obtains odd function signal U₈(t)；In the first signal processing mould In block, anticlockwise two-way quadrature demodulated signal U₅(t) and U₆(t), respectively square after be added, then open radical sign obtain it is non- Negative even function signal U₉(t), according to the positive negativity of quadrature demodulated signal all the way therein come to U₉(t) it is overturn, is finally obtained Odd function signal U₁₀(t)；

(4) gyro signal exports：Inverse time needle path signal is transmitted to instead after the processing of the first signal processing module as error signal Locking module is presented, feedback lock module carries out it feedback control tunable laser after ratio and integral operation processing；Up time Needle path signal after the processing of second signal processing module, as resonance type optical gyroscope signal, is exported to data logger.

5. a kind of detecting system of the resonance type optical gyroscope based on quadrature demodulation, which is characterized in that it includes tunable laser Device, optical isolator, optical splitters, first phase modulator, second phase modulator, third phase modulator, optics are humorous Shake chamber, photoelectric conversion module form optical system and the modulation /demodulation module, feedback lock module, the first signal by signal The signal processing system that processing module, second signal processing module, servo shift frequency module are formed；

Tunable laser, optical isolator and optical splitters are sequentially connected, and optical splitters are modulated respectively with first phase Device, second phase modulator are connected, and first phase modulator, third phase modulator and optical resonator are sequentially connected, and second Phase-modulator is connected with optical resonator, and optical resonator, photoelectric conversion module and modulating and demodulating signal module are sequentially connected, Modulating and demodulating signal module is connected with first phase modulator, and modulating and demodulating signal module is connected with second phase modulator, letter Number modulation /demodulation module, the first signal processing module, feedback lock module and tunable laser are sequentially connected, signal modulation solution Mode transfer block, second signal processing module, servo shift frequency module and third phase modulator are sequentially connected.

6. the detecting system of the resonance type optical gyroscope based on quadrature demodulation as claimed in claim 5, it is characterised in that described Optical resonator be optical fibre device or integrated optical device.

7. the detecting system of the resonance type optical gyroscope based on quadrature demodulation as claimed in claim 5, it is characterised in that described Optical resonator structure be transmitted light resonator or reflective optic resonator.

8. a kind of detection method using detecting system described in claim 4, which is characterized in that include the following steps：

(1) phase-modulation：The laser sent out by tunable laser is divided into work(after optical isolator, by optical splitters Two identical beams of rate, then respectively by first phase modulator and second phase modulators modulate, specifically：Signal modulation solution Mode transfer block generates carrier suppressed modulation signal U₁(t) and U₂(t) it respectively drives first phase modulator and second phase modulator is complete Into phase-modulation, phase-modulation and carrier wave this completes the light counterclockwise and clockwise to entering optical resonator press down System；

(2) quadrature demodulation of signal：By the two-beam of phase-modulation, optical resonator is inputted, is formed counterclockwise and clockwise Two resonance light beams, this two-beam respectively enters photodetector and is converted into electric signal；Modulating and demodulating signal module generates same The electric signal that frequency orthogonal signalling are respectively converted into light beam clockwise is demodulated, and generates demodulated signal U₃(t) and U₄(t)；Signal The electric signal that the generation of modulation /demodulation module is respectively converted into light beam counterclockwise with frequency orthogonal signalling is demodulated, and generates demodulation letter Number U₅(t) and U₆(t)；

(3) signal processing of quadrature demodulated signal：In second signal processing module, clockwise two-way quadrature demodulation letter Number U₃(t) and U₄(t), respectively square after be added, then open radical sign and obtain non-negative even function signal U₇(t), according to it is therein all the way The positive negativity of quadrature demodulated signal is come to U₇(t) it is overturn, finally obtains odd function signal U₈(t)；In the first signal processing mould In block, anticlockwise two-way quadrature demodulated signal U₅(t) and U₆(t), respectively square after be added, then open radical sign obtain it is non- Negative even function signal U₉(t), according to the positive negativity of quadrature demodulated signal all the way therein come to U₉(t) it is overturn, is finally obtained Odd function signal U₁₀(t)。

(4) gyro signal exports：Inverse time needle path signal is transmitted to feedback lock after the first signal processing module as error signal Cover half block, feedback lock module carry out it feedback control tunable laser after ratio and integral operation processing, up time needle path Signal after second signal processing module, is transmitted to servo shift frequency module, finally acts on third phase modulator so that suitable When needle path be also operated on resonant frequency point, shift frequency amount is the rotation output signal of gyro.