CN109357672B - A bidirectional optical carrier microwave resonance system based on circulator structure and method for detecting angular velocity - Google Patents

Abstract

The invention discloses a bidirectional optical carrier microwave resonance system based on a circulator structure and a method for detecting angular velocity. The invention utilizes the regenerative mode locking technology, the cavity length control technology and the polarization state separation technology to generate high-stability light-carrying microwaves in the optical fiber ring with the forward and reverse bidirectional polarization states vertical, and is used for measuring the rotation angular velocity. The invention adopts the circulator structure, realizes the bidirectional optical carrier microwave resonance through the bidirectional regeneration mode locking technology; realizes the reciprocal bidirectional optical carrier microwave resonance system based on the non-reciprocal error elimination technology of the broad-spectrum optical interferometer; adopts the polarization state Separation technology realizes dual-wavelength separation of optical signals, and uses vertical polarization states to transmit in opposite directions in the sensitive ring to improve the detection capability of the sensitive ring; the cavity length control technology is used to lock the microwave oscillation frequency in one direction to a high-stability standard time reference On the source, the relative cavity length of the optical resonator is stabilized. The system and method of the invention have the characteristics of strong practicability and high measurement accuracy.

Description

A bidirectional optical carrier microwave resonance system based on circulator structure and its detection angular velocity degree method

technical field

The invention belongs to the technical field of high-precision optical gyroscopes, and in particular relates to a bidirectional optical carrier microwave resonance system based on a circulator structure and a method for detecting angular velocity thereof.

Background technique

In the field of inertial navigation, an accelerometer is usually used to detect the translational velocity of the carrier, and a gyroscope is used to detect the rotational angular velocity of the carrier. There are mainly two types of high-precision gyroscopes, mechanical gyroscopes and optical gyroscopes, which are widely used in military, industrial, scientific and other fields. Among them, optical gyroscopes mainly include laser gyroscopes and fiber optic gyroscopes. Although the laser gyroscope has high precision, it has a blocking effect and high maintenance costs; the interferometric fiber optic gyroscope has defects such as low optical power utilization, temperature error, and parasitic noise, and the detection accuracy is low; the resonant fiber optic gyroscope is easy to miniaturize, but it is not suitable for The light source requirements are very high, and the practicability needs to be improved at present. Although compared with mechanical gyroscopes, the overall stability of optical gyroscopes is still insufficient, but its compact structure and high sensitivity make optical gyroscopes still occupy an important share in the market of high-precision gyroscopes.

The basic principle of the optical gyroscope to detect the rotational angular velocity of the carrier is the Sagnac effect. The basic principle of the Sagnac effect is that in a closed optical path, two beams of light transmitted in a clockwise (CW) and counterclockwise (CCW) direction from the same light source have different optical path differences due to the rotation of the carrier, thereby generating a phase. difference or frequency difference. Since the generated phase difference or frequency difference is only related to the rotational angular velocity of the carrier, the measurement of the rotational angular velocity of the carrier can be realized by detecting the phase difference or frequency difference generated by the optical gyroscope. To realize Sagnac effect detection, it is first necessary to realize the clockwise (CW) and counterclockwise (CCW) transmission of the same light source. Due to the limitation of the bidirectional transmission capability of optoelectronic devices, the clockwise (CW) and counterclockwise directions The characteristics of the optical resonator (CCW) cannot be completely identical, so the introduced non-reciprocal error will reduce the accuracy of the light-borne microwave gyroscope. Therefore, high-precision and high-reliability optical gyroscopes are still the focus of gyroscope research.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the shortcomings of the existing optical gyro angular velocity measurement solutions, and to provide a bidirectional optical carrier microwave resonance system based on a circulator structure and a method for detecting the angular velocity.

In order to achieve the above object, the present invention adopts the following design scheme: a bidirectional optical carrier microwave resonance system based on a circulator structure, the system includes a broad-spectrum light source, a 50:50 coupler, a first wavelength division multiplexer, a second wave Demultiplexer, low-speed photoelectric converter, interferometer controller, cavity length compensation regulator, first optical amplifier, first photoelectric intensity modulator, first optical circulator, first optical coupler, narrow-band bidirectional optical filter , the second optical coupler, the second optical amplifier, the second photoelectric intensity modulator, the second optical circulator, the first regenerative cavity cavity length regulator, the first high-speed photodetector, the first microwave filtering and amplifying unit, the first Microwave power divider, second regenerative cavity cavity length regulator, second high-speed photodetector, second microwave filter and amplifying unit, sensitive ring interferometer structure, second microwave power divider, third microwave power divider and difference frequency detection unit;

The first optical amplifier, the first photoelectric intensity modulator, the cavity length compensation regulator, the first optical circulator, the second wavelength division multiplexer, the first optical coupler, the narrow-band bidirectional optical filter, and the sensitive ring interferometer The structure, the second optical coupler, the first wavelength division multiplexer and the second optical circulator are connected in sequence to form a clockwise ring resonant cavity; the clockwise resonant light passes through the first optical coupler and the second regenerating cavity in sequence. The regulator, the second high-speed photodetector, the second microwave filtering and amplifying unit, and the third microwave power divider feedback modulate the first photoelectric intensity modulator to form a clockwise regenerative mode-locking structure; The electrical signal is input to the difference frequency detection unit through the third microwave power divider;

The second optical amplifier, the second photoelectric intensity modulator, the second optical circulator, the first wavelength division multiplexer, the second optical coupler, the sensitive ring interferometer structure, the narrow-band bidirectional optical filter, the first optical coupling The second wavelength division multiplexer and the first optical circulator are connected in turn to form a counterclockwise ring resonator; the counterclockwise resonant light passes through the second optical coupler, the first regenerating cavity cavity length regulator, the first high-speed optoelectronic The detector, the first microwave filtering and amplifying unit, the first microwave power divider and the second microwave power divider feedback modulate the second photoelectric intensity modulator to form a counterclockwise regenerative mode-locking structure; The electrical signal is input to the difference frequency detection unit through the second microwave power divider;

The broadband light source, the 50:50 coupler, the first wavelength division multiplexer, the second wavelength division multiplexer, the low-speed photoelectric converter, the interferometer controller and the cavity length compensation regulator form a clockwise and counterclockwise double loop. Reciprocity error compensation broad-spectrum optical interferometer; the light emitted by the broad-spectrum light source is divided into two arms by a 50:50 coupler, and the first arm passes through the second wavelength division multiplexer, the first optical circulator, the first The second optical amplifier, the second photoelectric intensity modulator, the second optical circulator, the first wavelength division multiplexer, and the 50:50 coupler enter the low-speed photoelectric converter; the second arm passes through the first wavelength division multiplexer, the second Two optical circulators, a first optical amplifier, a first photoelectric intensity modulator, a cavity length compensation regulator, a first optical circulator, a second wavelength division multiplexer, and a 50:50 coupler enter the low-speed photoelectric converter; the The detection signal of the low-speed photoelectric converter passes through the interferometer controller, and the output controls the cavity length compensation regulator, so that the optical paths of the two arms of the broad-spectrum optical interferometer are the same, and the non-reciprocal error caused by the non-bidirectional devices on the two arms is eliminated; The light emitted by the broad-spectrum light source does not interfere with the clockwise resonant light and the counterclockwise resonant light;

The sensitive ring interferometer structure includes a first orthogonal polarization state adjustment unit, a polarization beam splitter, an optical fiber sensitive ring and a second orthogonal polarization state adjustment unit;

The clockwise resonant light passes through the first orthogonal polarization state adjustment unit to adjust the double-peak spectral signal of the narrow-band bidirectional optical filter into two-way signals with vertical polarization states, enters the fiber sensitive ring through the polarization beam splitter, and passes through the polarization beam splitter in turn. The device and the second orthogonal polarization state adjustment unit adjust the polarization state back to the initial state;

The counterclockwise resonant light passes through the second orthogonal polarization state adjustment unit to adjust the double-peak spectral signal of the narrow-band bidirectional optical filter into two-way signals with vertical polarization states, enters the optical fiber sensitive ring through the polarization beam splitter, and then passes through the polarization beam splitter in turn. The first orthogonal polarization state adjusting unit adjusts the polarization state back to the initial state.

Further, in the bidirectional optical carrier microwave resonance system based on the circulator structure, the microwave signal generated by the clockwise regenerative mode locking structure and the counterclockwise regenerative mode locking structure is input to the difference frequency detection unit for angular velocity detection.

Further, the narrow-band bidirectional optical filter changes the resonant optical carrier microwave signal during system operation into a double-peak spectral signal, the corresponding wavelengths of the spectral peaks are λ ₁ and λ ₂ respectively, and the frequency difference between λ ₁ and λ ₂ is the modulation signal. f _m , to achieve bidirectional dual-frequency resonance.

Further, in the sensitive ring interferometer structure, the first orthogonal polarization state adjustment unit and the second orthogonal polarization state adjustment unit are both realized by a plurality of polarization beam splitters and polarization state controllers.

Further, in the structure of the sensitive ring interferometer, the speed of light is different when the two signals with vertical polarization states are transmitted in the opposite direction in the sensitive ring, which increases the detection gain of the SAGNAC effect of the sensitive ring.

Further, the cavity length regulator of the first regeneration cavity and the cavity length regulator of the second regeneration cavity are used as optical path adjustment units, using optical fiber stretchers, adjustable optical delay lines or spatial optical displacement stages; The compensation adjuster is used as the arm length adjustment unit of the broad-spectrum interferometer, and adopts the fiber stretcher, the adjustable light delay line or the spatial light stage.

Further, the system also includes a cavity length control system, the cavity length control system includes a cavity length regulator, a cavity length control unit and an external clock reference source, the cavity length regulator is arranged in a bidirectional ring resonant cavity, the The first microwave power divider is input to the cavity length control unit, the external clock reference source is input to the cavity length control unit, and the cavity length control unit is connected to the cavity length regulator to realize the stability of the cavity length of the resonant cavity.

Further, the cavity length regulator includes a first stage cavity length regulator and a second stage cavity length regulator, the adjustment range of the first stage cavity length regulator is larger than that of the second stage cavity length regulator, and the first stage cavity length regulator has a larger adjustment range. The first-stage cavity length adjuster is used to adjust the cavity length at a slow speed, the second-stage cavity length adjuster is used to quickly adjust the cavity length, and the first-stage cavity length adjuster and the second-stage cavity length adjuster are used as optical path adjustment units , using a fiber stretcher, a dimmable delay line or a spatial optical stage.

A method for angular velocity detection using a bidirectional optical carrier microwave resonance system based on a circulator structure, the method comprising the following steps:

Step 1: The clockwise working light passes through the clockwise ring resonator and the clockwise regenerative mode-locking structure, and the third microwave power divider achieves a stable f1 frequency output;

The counterclockwise working light passes through the counterclockwise ring resonator and the counterclockwise regenerative mode-locking structure, and the second microwave power divider achieves a stable f2 frequency output;

Step 2: The clockwise working light and the counterclockwise working light produce opposite sagnac effects in the structure of the sensitive ring interferometer. The difference frequency detection unit detects the frequency difference between the frequency f1 and the frequency f2 obtained in step 1, that is, the beat frequency, Denoted as Δf;

Step 3: By the following formula, the rotational angular velocity Ω _r can be obtained

Among them, S is the area surrounded by the optical fiber sensitive ring in the sensitive ring interferometer structure, λ is the wavelength corresponding to frequency f1 or frequency f2, L is the total fiber length of the optical fiber sensitive ring; G ₁ is the clockwise working light entering the optical fiber sensitive ring , the gain due to the sensitive sagnac effect of two paths with vertical polarization states; G ₂ is the gain generated by the two paths of sensitive sagnac effect with the polarization state perpendicular to the light entering the optical fiber sensitive ring in the counterclockwise direction.

Further, when the bidirectional optical carrier microwave resonance system based on the circulator structure has a cavity length control system, the counterclockwise microwave frequency f1 distributed by the first microwave power divider and the external clock reference source are subjected to frequency and phase discrimination, and the output signal is obtained. The cavity length control unit is used to control the cavity length regulator to achieve counterclockwise cavity length locking; at this time, the clockwise cavity length change is the clockwise cavity length change and the cavity length before cavity length locking. The sum of the counterclockwise cavity length changes before locking.

The beneficial effects of the invention are as follows: the invention combines the bidirectional regeneration mode locking technology and the traditional resonant optical gyroscope technology to construct a bidirectional optical carrier microwave resonance system based on the Sagnac effect principle. The system obtains highly stable microwave oscillation by bidirectional photoelectric oscillation instead of traditional light wave oscillation, and is used for the measurement of rotational angular velocity; the system uses a broad-spectrum optical interferometer to compensate for the non-reciprocal error of clockwise and counterclockwise bidirectional, and realizes microwave resonance on light carrier The bidirectional structure of the system is reciprocal; the sensitive ring interferometer structure is used to adjust the polarization state of the signal light transmitted bidirectionally in the sensitive ring; , the former can detect the frequency difference by amplifying the frequency multiplication and other methods, improve the signal-to-noise ratio, so that the frequency stability of the microwave oscillation signal can reach 10 ^-13 ; lock the oscillation frequency in one direction to a standard time reference with higher stability On the source, such as an atomic clock, the relative cavity length of the photoelectric oscillator can be stabilized, the temperature drift and optical spurious noise of the fiber ring cavity are eliminated, and the frequency stability is further improved. The invention greatly improves the signal-to-noise ratio of the bidirectional oscillation beat frequency signal caused by the Sagnac effect. The system and method provided by the invention have the characteristics of strong practicability and high measurement accuracy, and can meet the application requirements of high-precision optical gyroscopes.

Description of drawings

1 is a block diagram of a bidirectional optical carrier microwave resonance system based on a circulator structure according to an embodiment of the present invention;

2 is a block diagram of a bidirectional optical carrier microwave resonance system based on a circulator structure according to another embodiment of the present invention;

Fig. 3 is the composition block diagram of the structure of the sensitive ring interferometer;

In the figure, broadband light source 1, 50:50 coupler 2, first wavelength division multiplexer 3, second wavelength division multiplexer 4, low-speed photoelectric converter 5, interferometer controller 6, cavity length compensation regulator 7. The first optical amplifier 9, the first photoelectric intensity modulator 10, the first optical circulator 11, the first optical coupler 12, the narrow-band bidirectional optical filter 13, the first-stage cavity length regulator 14, the second-stage Cavity length adjuster 15, second optical coupler 16, second optical amplifier 17, second photoelectric intensity modulator 18, second optical circulator 19, first regenerative cavity cavity length adjuster 20, first high-speed photodetector 21. The first microwave filtering and amplifying unit 22, the first microwave power divider 24, the second regenerating cavity length regulator 25, the second high-speed photodetector 26, the second microwave filtering and amplifying unit 27, the sensitive ring interferometer structure 29 , cavity length control unit 30, first orthogonal polarization state adjustment unit 37, polarization beam splitter 38, fiber sensitive ring 39, second orthogonal polarization state adjustment unit 40, external clock reference source 45, second microwave power divider 46. The third microwave power divider 47 and the difference frequency detection unit 48; the solid line in the figure represents the optical path connection, which is an optical path; the dotted line represents the microwave circuit connection, which is an electrical path.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

As shown in FIG. 1, this embodiment provides a bidirectional optical carrier microwave resonance system based on a circulator structure, which includes a broad-spectrum light source, a 50:50 coupler, a first wavelength division multiplexer 3, a second wavelength Demultiplexer 4, low-speed photoelectric converter 5, interferometer controller 6, cavity length compensation regulator 7, first optical amplifier 9, first photoelectric intensity modulator 10, first optical circulator 11, first optical coupling 12, narrow-band bidirectional optical filter 13, second optical coupler 16, second optical amplifier 17, second photoelectric intensity modulator 18, second optical circulator 19, first regeneration cavity cavity length regulator 20, first High-speed photodetector 21, first microwave filter amplifying unit 22, first microwave power divider 24, second regeneration cavity cavity length regulator 25, second high-speed photodetector 26, second microwave filter and amplifying unit 27, sensitive ring The interferometer structure 29, the second microwave power divider 46, the third microwave power divider 47 and the difference frequency detection unit 48;

The first optical amplifier 9, the first photoelectric intensity modulator 10, the cavity length compensation regulator 7, the first optical circulator 11, the second wavelength division multiplexer 4, the first optical coupler 12, the narrow-band bidirectional optical filter The device 13, the sensitive ring interferometer structure 29, the second optical coupler 16, the first wavelength division multiplexer 3 and the second optical circulator 19 are connected in sequence to form a clockwise ring resonator; the clockwise resonant light passes through the An optical coupler 12, a second regenerative cavity cavity length regulator 25, a second high-speed photodetector 26, a second microwave filter amplifying unit 27 and a third microwave power divider 47 feedback modulate the first photoelectric intensity modulator 10, forming a Clockwise regeneration of the mode-locked structure; the electrical signal generated by the clockwise regeneration of the mode-locked structure is input to the difference frequency detection unit 48 through the third microwave power divider 47; the second regeneration cavity cavity length adjuster 25 is used as an optical path adjustment unit , devices such as fiber stretchers, adjustable optical delay lines or spatial optical displacement stages can be used.

The second optical amplifier 17, the second photoelectric intensity modulator 18, the second optical circulator 19, the first wavelength division multiplexer 3, the second optical coupler 16, the sensitive ring interferometer structure 29, the narrow-band bidirectional optical filter The optical coupler 13, the first optical coupler 12, the second wavelength division multiplexer 4, and the first optical circulator 11 are sequentially connected to form a counterclockwise ring resonator; the counterclockwise resonant light passes through the second optical coupler 16, the first optical circulator The regenerative cavity cavity length regulator 20, the first high-speed photodetector 21, the first microwave filtering and amplifying unit 22, the first microwave power divider 24 and the second microwave power divider 46 feedback modulate the second photoelectric intensity modulator 18 to form The mode-locked structure is regenerated in the counterclockwise direction; the electrical signal generated by the regenerated mode-locked structure in the counterclockwise direction is input to the difference frequency detection unit 48 through the second microwave power divider 46 ; the first regeneration cavity cavity length adjuster 20 is used as an optical path adjustment unit , devices such as fiber stretchers, adjustable optical delay lines or spatial optical displacement stages can be used.

The broadband light source 1, the 50:50 coupler 2, the first wavelength division multiplexer 3, the second wavelength division multiplexer 4, the low-speed photoelectric converter 5, the interferometer controller 6 and the cavity length compensation regulator 7 A broad-spectrum optical interferometer with reciprocity error compensation composed of clockwise and counterclockwise double loops; the light emitted by the broad-spectrum light source 1 is divided into two arms by a 50:50 coupler 2, and the first arm passes through the second wavelength division multiplexing in turn 4, the first optical circulator 11, the second optical amplifier 17, the second photoelectric intensity modulator 18, the second optical circulator 19, the first wavelength division multiplexer 3, and the 50:50 coupler 2 into the low-speed photoelectric conversion The second arm passes through the first wavelength division multiplexer 3, the second optical circulator 19, the first optical amplifier 9, the first photoelectric intensity modulator 10, the cavity length compensation regulator 7, and the first optical circulator in sequence 11. The second wavelength division multiplexer 4 and the 50:50 coupler 2 enter the low-speed photoelectric converter 5; the detection signal of the low-speed photoelectric converter 5 passes through the interferometer controller 6 and outputs the control cavity length compensation regulator 7, The two arms of the broad-spectrum light interferometer have the same optical path, and the non-reciprocal error caused by the non-bidirectional devices on the two arms is eliminated; the light emitted by the broad-spectrum light source 1 does not interfere with the clockwise resonant light and the counterclockwise resonant light; The cavity length compensation adjuster 7 is used as an arm length adjustment unit of a broad-spectrum interferometer, and can use devices such as a fiber stretcher, a tunable light delay line, or a spatial optical displacement stage.

The sensitive ring interferometer structure 29 includes a first orthogonal polarization state adjustment unit 37, a polarization beam splitter 38, an optical fiber sensitive ring 39 and a second orthogonal polarization state adjustment unit 40;

The clockwise resonant light passes through the first orthogonal polarization state adjustment unit 37 to separate the double-peak spectral signal of the narrow-band bidirectional optical filter 13 into two optical signals whose center wavelengths are λ ₁ and λ ₂ respectively, and the polarization states are vertical. The beam splitter 38 is divided into λ ₁ and λ ₂ into the optical fiber sensitive ring 39 to sense the angular velocity, and then passes through the polarization beam splitter 38 to combine the beams. After the second orthogonal polarization state adjustment unit 40, the sensitive ring interferometer structure 29 is realized. The output signal is consistent with the polarization state of the input signal;

The counterclockwise resonant light passes through the second orthogonal polarization state adjustment unit 40 to separate the double-peak spectral signal of the narrow-band bidirectional optical filter 13 into two optical signals whose center wavelengths are λ ₁ and λ ₂ respectively, and the polarization states are vertical. The beam splitter 38 is divided into λ ₁ and λ ₂ into the optical fiber sensitive ring 39 to sense the angular velocity, and then passes through the polarization beam splitter 38 to combine the beams, and after the first orthogonal polarization state adjustment unit 37, the sensitive ring interferometer structure 29 is realized. The output signal has the same polarization state as the input signal.

The bidirectional optical carrier microwave resonance system based on the circulator structure adopts the clockwise regenerative mode-locking structure and the counterclockwise regenerative mode-locking structure to generate the microwave signal input to the microwave frequency difference detection unit 48 for angular velocity detection.

The narrow-band bidirectional optical filter 13 converts the resonant optical carrier microwave signal during system operation into a double-peak spectral signal, the corresponding wavelengths of the spectral peaks are λ ₁ and λ ₂ respectively, and the frequency difference between λ ₁ and λ ₂ is the modulation signal f _m . , to achieve two-way dual-frequency resonance.

In the sensitive ring interferometer structure, both the first orthogonal polarization state adjustment unit 37 and the second orthogonal polarization state adjustment unit 40 can be implemented by several polarization beam splitters and polarization state controllers.

In the structure of the sensitive ring interferometer, when the two optical signals with vertical polarization states are transmitted in opposite directions in the sensitive ring, the speed of light is different, and the detection gain of the SAGNAC effect of the sensitive ring is increased.

The λ ₁ wavelength signal that enters the sensitive ring in the counterclockwise direction has the same transmission path as the λ ₂ wavelength signal that enters the sensitive ring and transmits in the clockwise direction, and the polarization state is vertical _; The transmission path of the λ ₁ wavelength signal transmitted in the sensitive ring in the clockwise direction is the same, and the polarization state is vertical; the wavelength and polarization state of the clockwise and counterclockwise working optical signals are separated;

The sign of the optical path difference (phase difference) due to the sagnac effect is opposite in the clockwise and counterclockwise resonators, resulting in twice the optical path difference due to the unidirectional sagnac effect in the clockwise and counterclockwise directions.

A method for angular velocity detection using a bidirectional optical carrier microwave resonance system based on a circulator structure includes the following steps:

Step 1: The output light of the broadband light source 1 with the isolator is divided into two channels after the power is equally divided by the 50:50 coupler 2. The first channel is injected into the first wavelength division multiplexer 3, and then clockwise Pass through the second optical circulator 19, the first optical amplifier 9, the first photoelectric intensity modulator 10, the cavity length compensation adjuster 7 and the first optical circulator 11 in sequence, and finally output through the second wavelength division multiplexer 4; The two channels are injected into the second wavelength division multiplexer 4, and then pass through the first optical circulator 11, the second optical amplifier 17, the second optical intensity modulator 18 and the second optical circulator 19 in the counterclockwise direction, and finally pass through the first optical circulator 11, the second optical amplifier 17, the second optical intensity modulator 18 and the second optical circulator 19. A wavelength division multiplexer 3 outputs; the two output signals passing through the first wavelength division multiplexer 3 and the second wavelength division multiplexer 4 are coupled back through the same 50:50 coupler 2, and the interference superposition signal passes through the low-speed photoelectric The converter 5 performs photoelectric conversion, and feedback adjusts the cavity length compensation regulator 7 via the interferometer controller 6 to keep the two arms of the interferometer equal in length;

Step 2: The output light of the first optical amplifier 9 enters the common cavity in a clockwise direction through the first photoelectric intensity modulator 10 and the first optical circulator 11, first passes through the second wavelength division multiplexer 4 in the common cavity, and then passes through the second wavelength division multiplexer 4 in the common cavity. The first optical coupler 12 is divided into two paths, and one path continues through the narrow-band bidirectional optical filter 13 , the sensitive ring interferometer structure 29 , the second optical coupler 16 , the first wavelength division multiplexer 3 and the second optical circulator 19 After that, it re-enters the first optical amplifier 9 to form an optical resonant cavity; the other path first passes through the second regenerating cavity cavity length regulator 25, and then undergoes photoelectric conversion through the second high-speed photodetector 26, and then is sent to the second microwave filtering and amplifying unit 27. After microwave filtering and amplification, the third microwave power divider 47 is divided into two channels, and one channel is injected into the first photoelectric intensity modulator 10 for microwave modulation to form a regenerative mode-locked loop, and the other channel is used as a clockwise resonant microwave output f1; Adjusting the second regenerative cavity cavity length regulator 25 before the second high-speed photodetector 26 can change the phase of the microwave injected into the first photoelectric intensity modulator 10 by the regenerative mode-locking loop to achieve a stable f1 frequency output;

Step 3: The principle of regenerative mode locking in the counterclockwise direction is similar to that in the clockwise direction. The output light of the second optical amplifier 17 passes through the second photoelectric intensity modulator 18 and the second optical circulator 19 and enters the common cavity in the counterclockwise direction. The cavity is divided into two paths through the second optical coupler 16, and one path continues through the sensitive ring interferometer structure 29, the narrow-band bidirectional optical filter 13, the first optical coupler 12, the second wavelength division multiplexer 4, the first optical ring After the regenerator 11, it re-enters the second optical amplifier 17 to form an optical resonant cavity; the other path first passes through the first regenerator cavity length regulator 20, and then undergoes photoelectric conversion through the first high-speed photodetector 21, and then sends the first microwave The filtering and amplifying unit 22 performs microwave filtering and amplifying, and is divided into two paths through the first microwave power divider 24 and the second microwave power divider 46, and one path is injected into the second photoelectric intensity modulator 18 for microwave modulation to form a regenerative mode locking loop , one channel is the counterclockwise resonant microwave output f2; the first regeneration cavity cavity length regulator 20 before the first high-speed photodetector 21 can be adjusted to change the phase of the microwave injected into the second photoelectric intensity modulator 18 by the regeneration mode locking loop, To achieve stable f2 frequency output;

Step 4: The clockwise working light and the counterclockwise working light produce opposite sagnac effects in the sensitive ring interferometer structure 29, and the difference frequency detection unit 48 detects the frequency difference between the frequency f1 and the frequency f2 obtained in step 1. frequency, recorded as Δf;

Step 5: The rotational angular velocity Ω _r can be obtained by the following formula

Among them, S is the area surrounded by the optical fiber sensitive ring in the sensitive ring interferometer structure, λ is the wavelength corresponding to frequency f1 or frequency f2, L is the total fiber length of the optical fiber sensitive ring; G ₁ is the clockwise working light entering the optical fiber sensitive ring , the gain due to the sensitive sagnac effect of two paths with vertical polarization states; G ₂ is the gain generated by the two paths of sensitive sagnac effect with the polarization state perpendicular to the light entering the optical fiber sensitive ring in the counterclockwise direction.

Example 2

As shown in FIG. 2 , a bidirectional optical carrier microwave resonance system based on a circulator structure provided in this embodiment, on the basis of Embodiment 1, further includes a cavity length control system, and the cavity length control system includes cavity length adjustment controller, cavity length control unit 30 and external clock reference source 45.

The cavity length regulator is arranged in a bidirectional ring resonant cavity, the first microwave power divider 24 is input to the cavity length control unit 30, the external clock reference source 45 is input to the cavity length control unit 30, and the cavity length control unit 30 is connected to the cavity length regulator to realize the stability of the cavity length of the resonant cavity.

Further, the cavity length regulator includes a first stage cavity length regulator 14 and a second stage cavity length regulator 15 , and the adjustment range of the first stage cavity length regulator 14 is larger than that of the second stage cavity length regulator 15 , the first-stage cavity length adjuster 14 is used to adjust the cavity length at a slow speed, the second-stage cavity length adjuster 15 is used to quickly adjust the cavity length, and the first-stage cavity length adjuster 14 and the second-stage cavity length adjuster 14 The cavity length adjuster 15 is used as an optical path adjustment unit, and adopts an optical fiber stretcher, a tunable light delay line or a spatial optical displacement stage.

The counterclockwise microwave frequency f1 distributed by the first microwave power divider 24 is subjected to frequency and phase discrimination with the external clock reference source 45, and the output signal is used to control the cavity length regulator through the cavity length control unit 30, so as to realize the counterclockwise resonant cavity Long locking; at this time, the clockwise resonator length change is the sum of the clockwise resonator length change before cavity length locking and the counterclockwise resonator length change before cavity length locking.

Those skilled in the art can easily make various changes and modifications according to the written description, drawings and claims provided by the present invention without departing from the spirit and scope of the present invention defined by the claims. Any modifications and equivalent changes made to the above embodiments according to the technical idea and essence of the present invention fall within the protection scope defined by the claims of the present invention.

Claims (10)

1. A bidirectional optical carrier microwave resonance system based on a circulator structure, characterized in that the system comprises a broad-spectrum light source (1), a 50:50 coupler (2), a first wavelength division multiplexer (3), A second wavelength division multiplexer (4), a low-speed photoelectric converter (5), an interferometer controller (6), a cavity length compensation regulator (7), a first optical amplifier (9), and a first photoelectric intensity modulator (10), a first optical circulator (11), a first optical coupler (12), a narrow-band bidirectional optical filter (13), a second optical coupler (16), a second optical amplifier (17), a second optical A photoelectric intensity modulator (18), a second optical circulator (19), a first regenerating cavity cavity length regulator (20), a first high-speed photodetector (21), a first microwave filtering and amplifying unit (22), a first a microwave power divider (24), a second regeneration cavity cavity length regulator (25), a second high-speed photodetector (26), a second microwave filter amplifying unit (27), a sensitive ring interferometer structure (29), A second microwave power divider (46), a third microwave power divider (47) and a difference frequency detection unit (48); the first optical amplifier (9), the first photoelectric intensity modulator (10), the cavity length compensation regulator (7), the first optical circulator (11), the second wavelength division multiplexer (4), the an optical coupler (12), a narrow-band bidirectional optical filter (13), a sensitive ring interferometer structure (29), a second optical coupler (16), a first wavelength division multiplexer (3) and a second optical ring The resonator (19) is sequentially connected to form a clockwise ring resonant cavity; the clockwise resonant light passes through the first optical coupler (12), the second regenerating cavity cavity length regulator (25), and the second high-speed photodetector (26) in sequence. ), the second microwave filter amplifying unit (27) and the third microwave power divider (47) to feedback modulate the first photoelectric intensity modulator (10) to form a clockwise regenerative mode-locking structure; the clockwise regenerative mode-locking structure generates The electrical signal is input to the difference frequency detection unit (48) through the third microwave power divider (47); The second optical amplifier (17), the second photoelectric intensity modulator (18), the second optical circulator (19), the first wavelength division multiplexer (3), the second optical coupler (16), the sensitive The ring interferometer structure (29), the narrow-band bidirectional optical filter (13), the first optical coupler (12), the second wavelength division multiplexer (4) and the first optical circulator (11) are connected in sequence to form a counterclockwise direction A ring resonator; the counterclockwise resonant light sequentially passes through a second optical coupler (16), a first regenerating cavity cavity length regulator (20), a first high-speed photodetector (21), and a first microwave filtering and amplifying unit (22) ), the first microwave power divider (24) and the second microwave power divider (46) feedback modulate the second photoelectric intensity modulator (18) to form a counterclockwise regenerative mode-locking structure; the counterclockwise regenerative mode-locking structure generates The electrical signal is input to the difference frequency detection unit (48) through the second microwave power divider (46); The broadband light source (1), a 50:50 coupler (2), a first wavelength division multiplexer (3), a second wavelength division multiplexer (4), a low-speed photoelectric converter (5), and an interferometer The controller (6) and the cavity length compensation regulator (7) form a clockwise and counterclockwise double-loop reciprocity error compensation broad-spectrum optical interferometer; the light emitted by the broad-spectrum light source (1) passes through a 50:50 coupler ( 2) Divided into two arms, the first arm passes through the second wavelength division multiplexer (4), the first optical circulator (11), the second optical amplifier (17), the second photoelectric intensity modulator (18), The second optical circulator (19), the first wavelength division multiplexer (3), and the 50:50 coupler (2) enter the low-speed photoelectric converter (5); the second arm sequentially passes through the first wavelength division multiplexer ( 3), a second optical circulator (19), a first optical amplifier (9), a first photoelectric intensity modulator (10), a cavity length compensation regulator (7), a first optical circulator (11), a second The wavelength division multiplexer (4) and the 50:50 coupler (2) enter the low-speed photoelectric converter (5); the detection signal of the low-speed photoelectric converter (5) passes through the interferometer controller (6) and outputs the control cavity The long compensation adjuster (7) realizes that the optical paths of the two arms of the broad-spectrum optical interferometer are the same, and eliminates the non-reciprocal error caused by the non-bidirectional devices on the two arms; the light emitted by the broad-spectrum light source (1) resonates clockwise Neither the light nor the counterclockwise resonant light interferes; The sensitive ring interferometer structure (29) comprises a first orthogonal polarization state adjustment unit (37), a polarization beam splitter (38), an optical fiber sensitive ring (39) and a second orthogonal polarization state adjustment unit (40); The clockwise resonant light passes through the first orthogonal polarization state adjusting unit (37) to adjust the double-peak spectral signal of the narrow-band bidirectional optical filter (13) into two-way signals with vertical polarization states, and enters through the polarization beam splitter (38) an optical fiber sensitive ring (39), the polarization state is adjusted back to the initial state through the polarization beam splitter (38) and the second orthogonal polarization state adjustment unit (40) in sequence; The counterclockwise resonant light passes through the second orthogonal polarization state adjustment unit (40) to adjust the double-peak spectral signal of the narrow-band bidirectional optical filter (13) into two-way signals with vertical polarization states, and enters through the polarization beam splitter (38) The optical fiber sensitive ring (39) adjusts the polarization state back to the initial state through the polarization beam splitter (38) and the first orthogonal polarization state adjustment unit (37) in sequence. 2. a kind of bidirectional optical carrier microwave resonance system based on circulator structure according to claim 1, it is characterized in that, adopt the microwave signal input difference frequency that clockwise regeneration mode locking structure and counterclockwise regeneration mode locking structure produce A detection unit (48) performs angular velocity detection. 3. a kind of bidirectional optical carrier microwave resonant system based on circulator structure according to claim 1, is characterized in that, described narrow-band bidirectional optical filter (13) changes the resonant optical carrier microwave signal during system operation into For a double-peak spectral signal, the corresponding wavelengths of the spectral peaks are λ ₁ and λ ₂ respectively, and the frequency difference between λ ₁ and λ ₂ is the modulation signal f _m , which realizes two-way dual-frequency resonance. 4. A bidirectional optical carrier microwave resonance system based on a circulator structure according to claim 1, characterized in that, in the sensitive ring interferometer structure (29), the first orthogonal polarization state adjustment unit (37) and the second orthogonal polarization state adjusting unit (40) are both realized by several polarization beam splitters and polarization state controllers. 5. A kind of bidirectional optical carrier microwave resonant system based on circulator structure according to claim 1, it is characterized in that, in described sensitive ring interferometer structure (29), the two-way signal whose polarization state is vertical is in sensitive ring The speed of light is different when transmitting in opposite directions, and the detection gain of the SAGNAC effect of the sensitive ring is increased. 6. A bidirectional optical carrier microwave resonance system based on a circulator structure according to claim 1, characterized in that the first regeneration cavity cavity length regulator (20) and the second regeneration cavity cavity length regulator ( 25) As an optical path adjustment unit, an optical fiber stretcher, a tunable optical delay line or a spatial optical displacement stage are used; the cavity length compensation adjuster (7) is used as a broad-spectrum interferometer arm length adjustment unit, and an optical fiber tensioner is used device, dimmable delay line or spatial optical stage. 7 . The bidirectional optical carrier microwave resonance system based on the circulator structure according to claim 1 , wherein the system further comprises a cavity length control system, and the cavity length control system comprises a cavity length regulator, a cavity length A control unit (30) and an external clock reference source (45), the cavity length regulator is arranged in the clockwise ring resonator and the counterclockwise ring resonator, and the first microwave power divider (24) is input into the cavity A length control unit (30), the external clock reference source (45) is input to the cavity length control unit (30), and the cavity length control unit (30) is connected to a cavity length regulator to realize the stability of the cavity length of the resonant cavity. 8. A bidirectional optical carrier microwave resonance system based on a circulator structure according to claim 7, wherein the cavity length adjuster comprises a first-stage cavity length adjuster (14) and a second-stage cavity length adjuster A regulator (15), the adjustment range of the first-stage cavity length regulator (14) is larger than that of the second-stage cavity length regulator (15), and the first-stage cavity length regulator (14) is used for slow adjustment Cavity length, the second-stage cavity length adjuster (15) is used to quickly adjust the cavity length, and the first-stage cavity length adjuster (14) and the second-stage cavity length adjuster (15) are used as optical path adjustment units , using a fiber stretcher, a dimmable delay line or a spatial optical stage. 9. A method for angular velocity detection using a bidirectional optical carrier microwave resonance system based on a circulator structure according to claim 7, wherein the method comprises the following steps: Step 1: The clockwise working light passes through the clockwise ring resonant cavity and the clockwise mode-locking structure, and achieves a stable f1 frequency output through the third microwave power divider (47); The counterclockwise working light passes through the counterclockwise ring resonator and the counterclockwise regenerative mode-locking structure, and the second microwave power divider (46) realizes a stable f2 frequency output; Step 2: The clockwise working light and the counterclockwise working light produce opposite sagnac effects in the sensitive ring interferometer structure (29), and the difference frequency detection unit (48) detects the frequency f1 and the frequency f2 obtained in step 1. The frequency difference is the beat frequency, recorded as Δf; Step 3: By the following formula, the rotational angular velocity Ω _r can be obtained

Among them, S is the area surrounded by the optical fiber sensitive ring in the sensitive ring interferometer structure, λ is the wavelength corresponding to frequency f1 or frequency f2, L is the total fiber length of the optical fiber sensitive ring; G ₁ is the clockwise working light entering the optical fiber sensitive ring , the gain due to the sensitive sagnac effect of two paths with vertical polarization states; G ₂ is the gain generated by the two paths of sensitive sagnac effect with the polarization state perpendicular to the light entering the optical fiber sensitive ring in the counterclockwise direction. 10. The method according to claim 9, characterized in that, when the bidirectional optical carrier microwave resonance system based on the circulator structure has a cavity length control system, the counterclockwise microwave distributed by the first microwave power divider (24) The frequency f1 and the external clock reference source (45) are used for frequency and phase discrimination, and the output signal is used to control the cavity length regulator through the cavity length control unit (30) to realize the counterclockwise resonant cavity length locking; at this time, the clockwise resonance The cavity length variation is the sum of the clockwise resonant cavity length variation before cavity length locking and the counterclockwise resonant cavity length variation before cavity length locking.

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