Wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback and RIN suppression method of wide-spectrum light source driven resonant optical gyroscope

Abstract

The invention belongs to the field of optical gyroscopes. The invention particularly relates to a wide-spectrum light source driven resonant optical gyroscope based on a light intensity fluctuation feedback technology and an RIN suppression method of the wide-spectrum light source driven resonant optical gyroscope. The light source ASE is connected with a first port of the circulator CIR, a second port of the circulator CIR is connected with the micro integrated optical waveguide modulator MIOC, the tail end of the micro integrated optical waveguide modulator MIOC is connected with one end of the coupler C1 and one end of the coupler C2, the other end of the coupler C1 and the other end of the coupler C2 are connected with the optical fiber resonant cavity FRR, and the optical fiber resonant cavity FRR is connected with the optical fiber resonant cavity FRR. Therefore, multi-circle transmission of light in the FRR is realized; a polarization maintaining optical fiber extending from the right transmission end of the coupler C2 is connected with the third output end of the circulator CIR after being welded by 90 degrees and then connected with one side of the coupler C3, and a light intensity signal output by the coupler C3 is detected by a photoelectric detector PD, passes through a lock-in amplifier LIA and a low-pass filter LPF and then serves as a rotating speed value to be output. According to the invention, light intensity fluctuation caused by a light source at a specific frequency can be actively suppressed.

Description

Technical Field

[0001] The present invention belongs to the field of optical gyroscopes, and specifically relates to a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback and a RIN suppression method thereof. Background Art

[0002] A gyroscope is a sensor that can accurately determine the angular velocity of a moving object. It is an inertial navigation instrument widely used in modern aviation, navigation, aerospace and defense industries. In recent years, under the demand of major national projects, the rapid development of inertial technology has put forward higher requirements for inertial devices. While ensuring that high-precision requirements are met, it is also required to have characteristics such as micro volume, low power consumption, high reliability, low cost and resistance to vibration and shock. The development level of gyroscopes directly affects the key performance of inertial navigation and guidance systems, and plays an irreplaceable role in the field of national defense.

[0003] Currently in the field of optical gyroscopes, laser gyroscopes have many internal optoelectronic components, which are difficult to manufacture and costly. The accuracy of interferometric fiber gyroscopes is related to the length of the internal fiber loop. High-precision interferometric fiber gyroscopes require loops several kilometers long, which makes them difficult to design for miniaturization. In contrast, resonant optical gyroscopes detect the angular velocity of rotation by detecting the resonant frequency difference of the oppositely transmitted light beams in the cavity caused by the Sagnac effect. The resonant cavity is used as its core sensitive component. The smallest micro cavity can reach the millimeter level, which conforms to the development trend of device miniaturization and has high processing repeatability, device integration capability and sensitivity.

[0004] Recently, a resonant fiber gyroscope driven by a broadband light source has been proposed to reduce coherent noise. This scheme has a simple optical configuration and signal processing method because there is no need for laser frequency locking or other complex coherent noise processing. This method suppresses optical noise, such as backscatter noise, and the light intensity fluctuation noise of the light source has become the main error source of the gyroscope output. In order to suppress the relative intensity noise (RIN) that has a great impact on the angle random walk (ARW), a high-frequency modulation technique is proposed. This method analyzes the RIN spectrum and optimizes the modulation frequency to demodulate the gyroscope signal at the lowest RIN. Another method suppresses RIN by establishing a relationship between the demodulation slope and RIN. By optimizing the modulation parameters and improving the fineness of the FRR, a steep slope can be achieved, thereby reducing the error caused by RIN. The above method provides a passive way to suppress RIN, so that the gyroscope operates at the lowest point in the noise spectrum. Therefore, the short-term accuracy of the gyroscope still depends on the background noise of the light source. Summary of the invention

[0005] The present invention provides a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, which can actively suppress light intensity fluctuation caused by a light source at a specific frequency.

[0006] The present invention provides a method for suppressing a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, which can actively suppress light intensity fluctuation caused by a light source at a specific frequency.

[0007] The present invention is achieved through the following technical solutions: A wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, the gyroscope comprising a light source ASE, a circulator CIR, a micro-integrated optical waveguide modulator MIOC, a coupler C1, a coupler C2, a fiber resonant cavity FRR, a coupler C3, a photodetector PD, a lock-in amplifier LIA and a low-pass filter LPF; The light source ASE is connected to port No. 1 of the circulator CIR, port No. 2 of the circulator CIR is connected to a micro-integrated optical waveguide modulator MIOC, the tail end of the micro-integrated optical waveguide modulator MIOC is respectively connected to one end of a coupler C1 and one end of a coupler C2, and the other end of the coupler C1 and the other end of the coupler C2 are respectively connected to a fiber resonant cavity FRR, so as to realize multi-circle transmission of light in the fiber resonant cavity FRR; The polarization-maintaining optical fiber extended from the right transmission end of the coupler C2 is connected to the No. 3 output end of the circulator CIR after 90-degree fusion and then connected to one side of the coupler C3. The light intensity signal output by the coupler C3 is detected by the photodetector PD and output as the rotation speed value after passing through the phase-locked amplifier LIA and the low-pass filter LPF.

[0008] Further, the working light source ASE is used to generate a wide-spectrum rectangular light field; The circulator CIR is used to transmit the light field in the forward direction and split the light field to the coupler C3 when the light field is transmitted in the reverse direction; The micro-integrated optical waveguide modulator MIOC is used to modulate the frequency phase of the incident and outgoing light fields; The coupler C1, the coupler C2 and the fiber resonant cavity FRR together constitute a resonant angular velocity sensing element, which is an important part of producing the Sagnac effect; The coupler C3 is used to combine the feedback light output by the circulator CIR3 segment with the direct light output by the transmission end of C2 to offset the light intensity fluctuation at a specific frequency; The photodetector PD is used to receive the optical signal emitted by C3 and convert the optical signal into an electrical signal; The lock-in amplifier LIA is used to synchronously demodulate the signal and output the signal to the low-pass filter LPF and the micro-integrated optical waveguide modulator MIOC respectively; The low-pass filter LPF is used to filter the synchronously demodulated signal.

[0009] Furthermore, the gyroscope can also be driven by white light.

[0010] A RIN suppression method for a resonant optical gyroscope driven by a wide-spectrum light source based on light intensity fluctuation feedback, characterized in that the suppression method uses the above-mentioned wide-spectrum light source driven by the resonant optical gyroscope based on light intensity fluctuation feedback, and the suppression method comprises: After the light source ASE emits the light field required for angular velocity detection, the micro-integrated optical waveguide modulator MIOC performs phase modulation and beam splitting on the light field. The split light enters the fiber resonant cavity FRR respectively and propagates clockwise and counterclockwise along the fiber resonant cavity FRR. After multiple-turn transmission through the resonant cavity FRR, one beam of light is output by the coupler C2, and enters the coupler C3 after 90° fusion. The other beam of light is combined and returned by the micro-integrated optical waveguide modulator MIOC, and is output from the 3-port of the circulator CIR through the 2-port of the circulator CIR and enters the coupler C3. Since the two beams of light entering the coupler C3 are not on the same polarization axis, the light intensities of the two light fields are superimposed after passing through the coupler C3; The signal light output by the coupler C3 is detected by the photodetector PD, which converts the light intensity signal into an electrical signal, demodulates it through the phase-locked amplifier LIA, demodulates and strips out the speed signal carried in the modulated signal, and outputs it as a gyro speed signal through a low-pass filter LPF.

[0011] Furthermore, it is characterized in that, due to the influence of the lock-in amplifier LIA9, the light intensity fluctuation passing through the fiber resonator FRR is expressed as follows in the absence of modulation: (1) (2) (3) (4) in, is the coupling coefficient; is the transmission time delay of light in FRR; K is the transmission loss; B It is the superposition value of light intensity fluctuations; D is the range of light intensity fluctuations; b is the light intensity fluctuation function at the modulation frequency; w and is the focusing fluctuation frequency and its random phase caused by the relative intensity noise RIN; , cand L are the refractive index of the optical fiber, the speed of light, and the length of the FRR.

[0012] Furthermore, it is assumed that RIN exhibits sinusoidal fluctuations at a specific demodulation frequency; after time delay and superposition of different numbers of turns, it maintains its sinusoidal shape; Due to the fixed length difference of the light propagation path, the different phase differences that cause light intensity fluctuations need to be adjusted to ensure that the phase difference is .

[0013] A test method for a RIN suppression method of a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, the test method uses the RIN suppression method of a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback as described above, and the test method requires a specific frequency fluctuation phase difference test on the constructed optical path; Two photodetectors are placed after an idle port at one transmission end of the coupler C2 and port 3 of the circulator CIR; no modulation signal is applied to the micro-integrated optical waveguide modulator MIOC, but a signal generator SG is used to generate sine and cosine waves of the same frequency and phase; these two signals are multiplied by PD1 and PD2 respectively to calculate the phase difference.

[0014] Furthermore, the specific frequency fluctuation phase difference test is calculated as follows: (5) (6) (7) in, is the signal from PD1 or PD2; is the angular frequency of the signal from the signal generator SG; and and The signal output by SG Signals multiplied with sine and cosine waves; and yes and The signal processed by the low-pass filter LPF; by adjusting the signal frequency of SG from a lower frequency to a higher frequency, a series of test samples are obtained and ; The phase difference is calculated as .

[0015] Furthermore, after a series of samples are obtained through standardization and their statistical information is calculated, the phase difference of light intensity fluctuation under different modulation frequencies is obtained; the demodulation frequency is gradually adjusted until the demodulation phase difference is π.

[0016] Furthermore, the light source ASE emits white light to drive the resonant optical gyroscope.

[0017] The beneficial effects of the present invention are: The present invention uses an ASE wide-spectrum light source to drive a resonant optical gyroscope, effectively utilizes the optical power at the idle end of the coupler, and performs feedback compensation on it, which can offset the fluctuation of the light intensity of the light source at a specific frequency. In addition, this method belongs to active compensation for RIN suppression. Compared with the currently available passive method (making the gyroscope work at the lowest point of the noise power spectrum), this method can theoretically completely eliminate the light intensity fluctuation of a specific frequency, and has lower requirements on the relative intensity noise quality of the light source. By setting this structure, it is possible to effectively reduce light intensity fluctuations, reduce the impact of RIN on the gyroscope output, and effectively improve the accuracy of the random walk of the gyroscope angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention.

[0019] Figure 2 It is a schematic diagram of the optical path relative intensity noise spectrum test of the present invention.

[0020] Figure 3 It is a technical verification schematic diagram of the present invention.

[0021] Figure 4 The present invention is under different modulation and demodulation frequencies. Figure 3 Schematic diagram of the phase difference distribution of light intensity fluctuations obtained from the structural test, where (a) is 400kHz, (b) is 800kHz, (c) is 1500kHz, and (d) is 1830kHz. DETAILED DESCRIPTION

[0022] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0023] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0024] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0025] The following is attached to this application specification Figure 1-4 , the technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0027] Implementation Method 1 This embodiment provides a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, wherein the gyroscope includes a light source ASE, a circulator CIR, a micro-integrated optical waveguide modulator MIOC, a coupler C1, a coupler C2, a fiber resonant cavity FRR, a coupler C3, a photodetector PD, a lock-in amplifier LIA and a low-pass filter LPF; The light source ASE is connected to port No. 1 of the circulator CIR, and port No. 2 of the circulator CIR is connected to a micro-integrated optical waveguide modulator MIOC. After the micro-integrated optical waveguide modulator MIOC performs equal power beam splitting on the light beam, its tail end is respectively connected to one end of the coupler C1 and one end of the coupler C2, and the other end of the coupler C1 and the other end of the coupler C2 are respectively connected to the optical fiber resonant cavity FRR, so as to realize multi-circle transmission of light in the optical fiber resonant cavity FRR; The right transmission end interface of the coupler C1 is idle, and the polarization-maintaining optical fiber extended from the right transmission end of the coupler C2 is connected to the No. 3 output end of the circulator CIR after 90-degree fusion and then connected to one side of the coupler C3. The light intensity signal output by the coupler C3 is detected by the photodetector PD and output as the rotation speed value after passing through the phase-locked amplifier LIA and the low-pass filter LPF.

[0028] Furthermore, the working light source ASE is used to generate a wide-spectrum rectangular light field; The circulator CIR is used to transmit the light field in the forward direction and split the light field to the coupler C3 when the light field is transmitted in the reverse direction; The micro-integrated optical waveguide modulator MIOC is used to modulate the frequency (phase) of the incident and outgoing light fields; The coupler C1, the coupler C2 and the fiber resonant cavity FRR together constitute a resonant angular velocity sensing element, which is an important part of producing the Sagnac effect; The coupler C3 is used to combine the feedback light output by the circulator CIR3 segment with the direct light output by the transmission end of C2 to offset the light intensity fluctuation at a specific frequency; The photodetector PD is used to receive the optical signal emitted by C3 and convert the optical signal into an electrical signal; The lock-in amplifier LIA is used to synchronously demodulate the signal and output the signal to the low-pass filter LPF and the micro-integrated optical waveguide modulator MIOC respectively; The low-pass filter LPF is used to filter the synchronously demodulated signal.

[0029] Furthermore, the gyroscope can also be driven by white light.

[0030] Implementation Method 2 This embodiment provides a method for suppressing RIN of a resonant optical gyroscope driven by a wide-spectrum light source based on light intensity fluctuation feedback. The suppression method uses the wide-spectrum light source driven by the resonant optical gyroscope based on light intensity fluctuation feedback as described in Embodiment 1. The suppression method includes: After the light source ASE emits the light field required for angular velocity detection, the micro-integrated optical waveguide modulator MIOC performs phase modulation and beam splitting on the light field. The split light enters the fiber resonant cavity FRR respectively and propagates clockwise and counterclockwise along the fiber resonant cavity FRR. After multiple-turn transmission through the resonant cavity FRR, one beam of light is output by the coupler C2, and enters the coupler C3 after 90° fusion. The other beam of light is combined and returned by the micro-integrated optical waveguide modulator MIOC, and is output from the 3-port of the circulator CIR through the 2-port of the circulator CIR and enters the coupler C3. Since the two beams of light entering the coupler C3 are not on the same polarization axis, the light intensities of the two light fields are superimposed after passing through the coupler C3; The signal light output by the coupler C3 is detected by the photodetector PD, which converts the light intensity signal into an electrical signal, demodulates it through the phase-locked amplifier LIA, demodulates and strips out the speed signal carried in the modulated signal, and outputs it as a gyro speed signal through a low-pass filter LPF.

[0031] Specifically, most of the light output from C2 does not pass through the FRR, and its light intensity fluctuation is almost consistent with the light source ASE intensity fluctuation (no delay). The light returned from the CIR3 port after MIOC beam combination passes through multiple turns of FRR, so there is a certain delay in the light intensity fluctuation. Since the FRR length is fixed and the delay time is fixed, there is a certain phase difference between the light intensity fluctuation output from the C2 transmission end and the CIR3 segment.

[0032] In order to avoid unnecessary interference between the two beams of light at coupler C3, a 90° fusion point is set between couplers C2 and C3, so that the propagation axis of the light is converted (from the slow axis to the fast axis) when propagating in this section. At this time, the propagation axes of the two beams entering coupler C3 are different. When they are combined in coupler C3, they only superimpose the light intensity and do not interfere with each other to cause unnecessary additional light intensity fluctuations.

[0033] Furthermore, due to the influence of the phase-locked amplifier LIA9, only the specific RIN frequency component equal to the modulation frequency needs to be concerned. The coupling ratio between coupler C1 and coupler C25 is 98:2; in coupler C25, most of the light intensity fluctuations from ASE have no time delay. Only a small part of the light passing through the FRR will experience time delay, and the intensity of this part is very weak. These intensity fluctuations are reflected on two ports (coupler C2 port output and CIR port 3) and are accompanied by a phase delay of the intensity fluctuations. At CIR port 3, all light passing through the FRR is delayed, and its intensity is contributed by the superposition of light fields with different period numbers in the FRR.

[0034] The light intensity fluctuation passing through the fiber resonator FRR can be expressed as follows in the absence of modulation: (1) (2) (3) (4) in, is the coupling coefficient; is the transmission time delay of light in FRR; K is the transmission loss; B It is the superposition value of light intensity fluctuations; D is the range of light intensity fluctuations; b is the light intensity fluctuation function at the modulation frequency; w and is the focusing fluctuation frequency and its random phase caused by the relative intensity noise RIN; , c and L are the refractive index of the optical fiber, the speed of light, and the length of the FRR.

[0035] Furthermore, it is assumed that RIN exhibits sinusoidal fluctuations at a specific demodulation frequency; after time delay and superposition of different numbers of turns, this fluctuation almost maintains its sinusoidal shape in theoretical analysis and simulation; Due to the fixed length difference of the light propagation path, the different phase differences that cause light intensity fluctuations need to be adjusted to ensure that the phase difference is .

[0036] Implementation Method 3 This embodiment provides a test method for the RIN suppression method of a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, and the test method uses the RIN suppression method of a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback as described in Embodiment 2, and the test method requires a specific frequency fluctuation phase difference test on the constructed optical path; In order to conduct on-site phase difference testing, a verification experiment is set up. Two photodetectors (PD1, PD2) are placed after an idle port at the transmission end of the coupler C2 and port 3 of the circulator CIR. No modulation signal is required to be applied to the micro-integrated optical waveguide modulator MIOC. Instead, a signal generator SG (Signal Generator) is used to generate sine and cosine waves of the same frequency and phase. These two signals are multiplied by PD1 and PD2 respectively to calculate the phase difference.

[0037] Furthermore, the specific frequency fluctuation phase difference test is calculated as follows: (5) (6) (7) in, is the signal from PD1 or PD2; is the angular frequency of the signal from the signal generator SG; and and The signal output by SG Signals multiplied with sine and cosine waves; and yes and The signal processed by the low-pass filter LPF; by adjusting the signal frequency of SG from a lower frequency (lower than the fiber ring intrinsic frequency) to a higher frequency (higher than the fiber ring intrinsic frequency), a series of test samples can be obtained and ; The phase difference can be calculated as .

[0038] Furthermore, after a series of samples are obtained through standardization and their statistical information is calculated, the phase difference of light intensity fluctuation under different modulation frequencies can be obtained; the demodulation frequency is gradually adjusted until the demodulation phase difference is π.

[0039] Furthermore, the light source ASE emits white light to drive the resonant optical gyroscope.

[0040] Instructions attached Figure 3 The test results of the structure are as attached in the manual. Figure 4 As shown, (a)(b)(c)(d) are respectively Figure 3 Phase difference distribution collected when the structure is set to different demodulation frequencies. When the demodulation frequency is set to (b) 800 kHz, the phase difference is mainly concentrated around π (different optical path structures correspond to different optimal modulation frequencies). This distribution is similar to the Gaussian curve distribution, which is due to the random phase of the light intensity fluctuation and the probability wave distribution, rather than the perfect sine wave distribution. Whether the frequency increases or decreases, the distribution of the phase difference will deviate from π. This shows that at 800 kHz, the light intensity fluctuations at the idle port of coupler C2 and port 3 of the circulator CIR are anti-correlated. The coupling ratio of C3 can be adjusted to make the light intensity fluctuation amplitudes equal, so that the light intensity fluctuations at the corresponding frequencies are offset, thereby suppressing RIN.

Claims

1. A resonant optical gyroscope driven by a wide-spectrum light source based on light intensity fluctuation feedback, characterized in that: The gyroscope includes a light source ASE, a circulator CIR, a micro integrated optical waveguide modulator MIOC, a coupler C1, a coupler C2, a fiber resonator FRR, a coupler C3, a photodetector PD, a lock-in amplifier LIA and a low-pass filter LPF; The light source ASE is connected to port No. 1 of the circulator CIR, port No. 2 of the circulator CIR is connected to a micro-integrated optical waveguide modulator MIOC, the tail end of the micro-integrated optical waveguide modulator MIOC is respectively connected to one end of a coupler C1 and one end of a coupler C2, and the other end of the coupler C1 and the other end of the coupler C2 are respectively connected to a fiber resonant cavity FRR, so as to realize multi-circle transmission of light in the fiber resonant cavity FRR; The polarization-maintaining optical fiber extended from the right transmission end of the coupler C2 is connected to the No. 3 output end of the circulator CIR after 90-degree fusion and then connected to one side of the coupler C3. The light intensity signal output by the coupler C3 is detected by the photodetector PD and output as the rotation speed value after passing through the phase-locked amplifier LIA and the low-pass filter LPF.

2. The wide-spectrum light source driven resonant optical gyroscope according to claim 1, characterized in that: The working light source ASE is used to generate a wide-spectrum rectangular light field; The circulator CIR is used to transmit the light field in the forward direction and split the light field to the coupler C3 when the light field is transmitted in the reverse direction; The micro-integrated optical waveguide modulator MIOC is used to modulate the frequency phase of the incident and outgoing light fields; The coupler C1, the coupler C2 and the fiber resonant cavity FRR together constitute a resonant angular velocity sensing element, which is an important part of producing the Sagnac effect; The coupler C3 is used to combine the feedback light output by the circulator CIR3 segment with the direct light output by the transmission end of C2 to offset the light intensity fluctuation at a specific frequency; The photodetector PD is used to receive the optical signal emitted by C3 and convert the optical signal into an electrical signal; The lock-in amplifier LIA is used to synchronously demodulate the signal and output the signal to the low-pass filter LPF and the micro-integrated optical waveguide modulator MIOC respectively; The low-pass filter LPF is used to filter the synchronously demodulated signal.

3. The wide-spectrum light source driven resonant optical gyroscope according to claim 1, characterized in that: The gyroscope can also be driven using white light.

4. A RIN suppression method for a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, characterized in that: The suppression method uses a wide-spectrum light source based on light intensity fluctuation feedback technology as claimed in any one of claims 1 to 3 to drive a resonant optical gyroscope, and the suppression method comprises: After the light source ASE emits the light field required for angular velocity detection, the micro-integrated optical waveguide modulator MIOC performs phase modulation and beam splitting on the light field. The split light enters the fiber resonant cavity FRR respectively and propagates clockwise and counterclockwise along the fiber resonant cavity FRR. After multiple-turn transmission through the resonant cavity FRR, one beam of light is output by the coupler C2, and enters the coupler C3 after 90° fusion. The other beam of light is combined and returned by the micro-integrated optical waveguide modulator MIOC, and is output from the 3-port of the circulator CIR through the 2-port of the circulator CIR and enters the coupler C3. Since the two beams of light entering the coupler C3 are not on the same polarization axis, the light intensities of the two light fields are superimposed after passing through the coupler C3; The signal light output by the coupler C3 is detected by the photodetector PD, which converts the light intensity signal into an electrical signal, demodulates it through the phase-locked amplifier LIA, demodulates and strips out the speed signal carried in the modulated signal, and outputs it as a gyro speed signal through a low-pass filter LPF.

5. The RIN suppression method according to claim 4, characterized in that: Due to the influence of the lock-in amplifier LIA9, the light intensity fluctuation passing through the fiber resonator FRR is expressed as follows in the absence of modulation: (1) (2) (3) (4) in, is the coupling coefficient; is the transmission time delay of light in FRR; K is the transmission loss; B It is the superposition value of light intensity fluctuations; D is the range of light intensity fluctuations; b is the light intensity fluctuation function at the modulation frequency; w and is the focusing fluctuation frequency and its random phase caused by the relative intensity noise RIN; , c and L are the refractive index of the optical fiber, the speed of light, and the length of the FRR.

6. The RIN suppression method according to claim 5, characterized in that: Assume that RIN exhibits sinusoidal fluctuations at a specific demodulation frequency; after time delay and superposition of different numbers of turns, it maintains its sinusoidal shape; Due to the fixed length difference of the light propagation path, the different phase differences that cause light intensity fluctuations need to be adjusted to ensure that the phase difference is .

7. A test method for RIN suppression of a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback, characterized in that: The test method uses the RIN suppression method of a wide-spectrum light source driven resonant optical gyroscope based on light intensity fluctuation feedback as described in any one of claims 4-6, and the test method requires a specific frequency fluctuation phase difference test to be performed on the constructed optical path; Two photodetectors are placed after an idle port at one transmission end of the coupler C2 and port 3 of the circulator CIR; no modulation signal is applied to the micro-integrated optical waveguide modulator MIOC, but a signal generator SG is used to generate sine and cosine waves of the same frequency and phase; these two signals are multiplied by PD1 and PD2 respectively to calculate the phase difference.

8. The testing method according to claim 7, characterized in that: The specific frequency fluctuation phase difference test is calculated as follows: (5) (6) (7) in, is the signal from PD1 or PD2; is the angular frequency of the signal from the signal generator SG; and and The signal output by SG Signals multiplied with sine and cosine waves; and yes and The signal processed by the low-pass filter LPF; by adjusting the signal frequency of SG from a lower frequency to a higher frequency, a series of test samples are obtained and ; The phase difference is calculated as .

9. The testing method according to claim 8, characterized in that: After a series of samples are obtained through standardization and their statistical information is calculated, the phase difference of light intensity fluctuation under different modulation frequencies is obtained; the demodulation frequency is gradually adjusted until the demodulation phase difference is π.

10. The testing method according to claim 7, characterized in that: The light source ASE emits white light to drive the resonant optical gyroscope.

Images