Fiber-optic gyroscope and comb pulse error suppression system and method

Abstract

The application discloses a fiber-optic gyroscope and a comb pulse error suppression system and method. The fiber-optic gyroscope comprises a wide-spectrum light source, a fiber-optic interferometer, an electro-optic intensity modulator, a photoelectric detector and a signal processing circuit. The wide-spectrum light source is used to provide a wide-spectrum light signal to the fiber-optic interferometer. The fiber-optic interferometer is used to generate at least one light interference signal according to the wide-spectrum light signal and mechanical rotation. The electro-optic intensity modulator is used to suppress the comb pulse of the light interference signal according to at least one modulation signal. The photoelectric detector is used to generate an electric measurement signal according to the light interference signal after suppression. The signal processing circuit is used to modulate the waveform of the wide-spectrum light signal propagating reversely in the fiber-optic interferometer according to the electric measurement signal, and generate the modulation signal according to the electric measurement signal. The signal processing circuit is used to obtain the rotation information of the mechanical rotation according to the electric measurement signal. The embodiment of the application suppresses the influence caused by the comb pulse error from the root by improving the electro-optic intensity modulator and the signal processing circuit, expands the effective sampling interval of the light interference signal, and suppresses the zero-bias error caused by the demodulation of the electric measurement signal.

Description

Technical Field

[0001] This invention relates to the field of fiber optic sensing, and more specifically, to a fiber optic gyroscope and a comb pulse error suppression system and method. Background Technology

[0002] A fiber optic gyroscope is an all-solid-state angular velocity sensor. It boasts numerous advantages, including flexible and diverse structures, high reliability, long lifespan, and a wide range of accuracy adaptability. It has many applications in attitude measurement and control, navigation and guidance, and is one of the most mainstream inertial instruments of the 21st century.

[0003] The most common interferometric digital closed-loop fiber optic gyroscope scheme currently uses square wave modulation or a variant of square wave modulation. The non-ideal nature of the modulation waveform leads to the presence of comb-like pulses in the output optical signal of the fiber optic interferometer. Figure 1 The optical signal shown has comb-like pulse characteristics, and the ringing effect caused by the comb pulse is one of the important error sources of digital closed-loop fiber optic gyroscopes.

[0004] Traditional methods for handling comb pulses include sampling away from the pulse and its influence. However, in practice, it is very difficult to determine the extent of the comb pulse's influence under various temperature, vibration, and shock conditions, making it challenging to strategically place sampling points. Insufficient sampling points will result in the loss of valuable information, leading to reduced gyroscope output accuracy. Summary of the Invention

[0005] Based on this, a first aspect of the present invention discloses a fiber optic gyroscope. The fiber optic gyroscope includes a broadband light source, a fiber optic interferometer, an electro-optic intensity modulator, a photodetector, and a signal processing circuit. The broadband light source provides a broadband optical signal to the fiber optic interferometer. The fiber optic interferometer generates at least one optical interference signal based on the broadband optical signal and mechanical rotation. The electro-optic intensity modulator suppresses comb pulses of the optical interference signal based on at least one modulation signal. The photodetector generates an electrical measurement signal based on the suppressed optical interference signal. The signal processing circuit modulates the waveform of the backpropagating broadband optical signal within the fiber optic interferometer based on the electrical measurement signal, and generates the modulation signal based on the electrical measurement signal. The signal processing circuit also acquires rotation information of the mechanical rotation based on the electrical measurement signal.

[0006] In the disclosed embodiment of the invention, the electro-optic intensity modulator suppresses or attenuates the time-domain portion of the comb pulse of the optical interference signal according to the modulation signal.

[0007] In the disclosed embodiment of the invention, the signal processing circuit generates a modulation signal that can modulate the switching control timing of the electro-optic intensity modulator based on the electrical measurement signal.

[0008] In the disclosed embodiments of the invention, the electro-optic intensity modulator is a LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator.

[0009] In the disclosed embodiment of the invention, the signal processing circuit generates a square wave modulation signal based on the electrical measurement signal and the optical path parameters of the fiber optic interferometer, and modulates the waveform of the broadband optical signal propagating backward within the fiber optic interferometer based on the square wave modulation signal; the fiber optic interferometer generates the optical interference signal having the comb-shaped pulse based on a portion of the broadband optical signal propagating forward, a portion of the broadband optical signal propagating backward after modulation, and the mechanical rotation.

[0010] In the disclosed embodiments of the invention, the signal processing circuit is used for filtering, amplifying, sampling, and demodulating the electrical measurement signal.

[0011] In the disclosed embodiment of the invention, the signal processing unit drives the broadband light source to provide the output power of the broadband optical signal according to the electrical measurement signal.

[0012] A second aspect of this invention discloses a comb pulse error suppression system for a fiber optic gyroscope. Applied to a fiber optic gyroscope, the gyroscope includes a broadband light source, a fiber optic interferometer, and a photodetector. The suppression system includes an electro-optic intensity modulator and a signal processing circuit. The broadband light source provides a broadband optical signal to the fiber optic interferometer. The fiber optic interferometer generates at least one optical interference signal based on the broadband optical signal and mechanical rotation. The electro-optic intensity modulator suppresses the comb pulse of the optical interference signal based on at least one modulation signal. The photodetector generates an electrical measurement signal based on the suppressed optical interference signal. The signal processing circuit modulates the waveform of the backpropagating broadband optical signal within the fiber optic interferometer based on the electrical measurement signal, and generates the modulation signal based on the electrical measurement signal. The signal processing circuit also acquires rotation information of the mechanical rotation based on the electrical measurement signal.

[0013] The third aspect of this invention discloses a method for suppressing comb pulse errors in a fiber optic gyroscope. The method is applied to at least one fiber optic gyroscope, the fiber optic gyroscope including a broadband light source, a fiber optic interferometer, an electro-optic intensity modulator, a photodetector, and a signal processing circuit. The suppression method includes the following steps: the broadband light source provides a broadband optical signal to the fiber optic interferometer; the fiber optic interferometer generates at least one first optical interference signal based on the forward and backward propagation of the broadband optical signal and mechanical rotation occurring in inertial space; the photodetector generates a first electrical measurement signal based on the first optical interference signal; the signal processing circuit modulates the backward propagating broadband optical signal within the fiber optic interferometer with a long wave based on the first electrical measurement signal; the fiber optic interferometer generates a second optical interference signal with comb-shaped pulses based on a portion of the forward propagating broadband optical signal, a portion of the modulated backward propagating broadband optical signal, and the mechanical rotation; the photodetector generates a second electrical measurement signal based on the second optical interference signal with comb-shaped pulses; the signal processing circuit generates the modulation signal based on the second electrical measurement signal; and the electro-optic intensity modulator is used to suppress the time domain of the comb-shaped pulses of the second optical interference signal based on the modulation signal.

[0014] In the disclosed embodiment of the invention, the photodetector generates a third electrical measurement signal based on the suppressed second optical interference signal; the signal processing circuit obtains the rotation information of the mechanical rotation based on the third electrical measurement signal.

[0015] Compared with the prior art, the embodiments of the present invention, through improvements to the electro-optic intensity modulator and signal processing circuit, fundamentally suppress the influence caused by comb pulse error, expand the effective sampling range of optical interference signal, and suppress the zero bias error caused by demodulation of electrical measurement signal.

[0016] In view of the above-mentioned solutions, the present invention will describe in detail the disclosed exemplary embodiments with reference to the accompanying drawings, which will also make other features and advantages of the embodiments of the present invention clear. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the comb pulse signal of the optical interference signal according to an embodiment of the present invention;

[0019] Figure 2This is a schematic diagram of the structure of a fiber optic gyroscope according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the operation of the LiNbO3 waveguide Mach-Zehnder type electro-optic intensity modulator according to an embodiment of the present invention. Detailed Implementation

[0021] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0022] The first aspect of this invention discloses a fiber optic gyroscope and a comb pulse error suppression system and method to suppress errors caused by comb pulses in the fiber optic gyroscope. Regarding the comb pulse generation proposed in this embodiment, a square wave bias modulation signal is typically applied between two opposing optical signals of the fiber optic interferometer 2 in an interferometric digital closed-loop fiber optic gyroscope. The modulation frequency of the modulation signal is related to the eigenfrequency of the fiber optic interferometer 2. Comb pulse generation can also be caused by imperfect modulation of the optical signal by the modulation signal.

[0023] Specifically, issues arise such as the rising and falling edges of the modulated signal having durations, the square wave duty cycle not being strictly equal, and the modulation frequency being misaligned with the intrinsic frequency. Under these circumstances, the waveform of the optical interference signal output by fiber optic interferometer 2 will exhibit comb-like pulses synchronized with the level shift of the modulated signal. Furthermore, the intrinsic frequency of fiber optic interferometer 2 varies with temperature, causing the comb-like pulses in the optical interference signal to be temperature-dependent. Additionally, during the duration of the comb-like pulses, there is no available fiber optic gyroscope rotation speed information for demodulation, which also causes output drift in the fiber optic gyroscope.

[0024] For example, comb pulses can cause transient saturation in commonly used PIN-FET detectors and subsequent amplifiers. Because PIN-FET detectors have a recovery time after saturation, the maximum feedback impedance of the gain element of the PIN-FET detector is limited by the pulse amplitude rather than the useful signal amplitude. When the PIN-FET detector recovers from overload, additional signal distortion occurs, leading to sampling and demodulation errors in the output electrical measurement signal of the PIN-FET detector.

[0025] For example, comb pulses exhibit temperature instability. The instability of the comb pulse and pulse decay can affect the output accuracy of fiber optic gyroscopes due to ringing effects. Specifically, although the fiber optic gyroscope samples the signal after peak decay, the differential signals after different peak decays can cause angular rate measurement errors. Temperature instability of the comb pulse can lead to instability in the output of the fiber optic gyroscope.

[0026] For example, the amplitude of the comb pulse limits the amplitude of the effective probe light power, which in turn limits the allowable gain of the signal processing circuit 5, the noise level of the fiber optic gyroscope output, and the bandwidth of the fiber optic gyroscope.

[0027] For example, comb pulses exhibit asymmetry. This is caused by differences in the rising and falling edges and modulation amplitude of the modulation waveform. Pulse asymmetry leads to odd harmonic components of the modulation frequency, causing pulse energy diffusion. During signal demodulation, this is accompanied by a Sagnac phase shift, resulting in gyroscope output error. Particularly concerning the second point, as temperature changes, the intrinsic frequency of the fiber optic interferometer drifts, increasing the misalignment between the modulation frequency and the intrinsic frequency, producing temperature-dependent bias errors.

[0028] Regarding the suppression or attenuation of comb pulses, from the waveform of the modulated signal, due to the unequal rise and fall times of the modulated square wave, the duty cycle becomes non-ideal as the intrinsic frequency changes with temperature. This results in even-order cosine harmonics in the modulated signal waveform, which in turn induce odd-order sine harmonics in the fiber optic gyroscope output. This leads to bias errors in the demodulated output during square wave demodulation. Similarly, from the waveform output of photodetector 4, the asymmetry of the spike pulse, when the intrinsic frequency changes with temperature, also induces odd-order sine harmonics in the fiber optic gyroscope output, resulting in bias errors. Since the optical interference signal is detected at photodetector 4, and the saturation problem of photodetector 4 persists, improvements to the analog switching circuit alone cannot suppress the differential rate demodulation error caused by pulse decay and ringing effects.

[0029] Based on this, this embodiment discloses an interferometric digital closed-loop fiber optic gyroscope. The fiber optic gyroscope uses square wave modulation or a variant of square wave modulation; the non-ideal nature of the modulated square wave waveform causes… Figure 1 The optical interference signal waveform shown exhibits comb-like pulse characteristics.

[0030] Please refer to Figure 2 and Figure 3 . Figure 2 A schematic diagram of the structure of a fiber optic gyroscope according to an embodiment of the present invention is provided. Figure 3 A schematic diagram of the structure of the electro-optic intensity modulator 3 according to an embodiment of the present invention is provided.

[0031] Figure 2 As shown, the fiber optic gyroscope of this embodiment includes a broadband light source 1, a fiber optic interferometer 2, an electro-optic intensity modulator 3, a photodetector 4, and a signal processing circuit 5. In this embodiment, the square wave modulation of the signal processing circuit 5 imparts comb-like pulse characteristics to the optical interference signal output by the fiber optic interferometer 2, and the electro-optic intensity modulator 3 suppresses or attenuates the comb-like pulses in the optical interference signal.

[0032] Among them, the broadband light source 1 provides the fiber optic interferometer 2 with a broadband optical signal that meets the requirements of optical power, spectral shape, polarization characteristics and other indicators.

[0033] Among them, the fiber optic interferometer 2 generates an optical interference signal based on the broadband optical signal and the mechanical rotation in inertial space. The optical interference signal carries the rotation speed information of the mechanical rotation.

[0034] Among them, the electro-optic intensity modulator 3 is a LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator 3. It is an optical modulator made using the Mach-Zehnder interference effect and the electro-optic effect, capable of splitting the input into two equal optical signals. Their phases change with the applied electrical signal, causing the intensity of the light after interference and combining to also change with the electrical signal, thus achieving intensity modulation. The LiNbO3 waveguide Mach-Zehnder electro-optic intensity modulator 3 effectively possesses attenuation and recovery capabilities for extremely high bandwidth optical signals. Broadband optical signals such as... Figure 3 This demonstrates how selective modulation of a portion of the time domain of an optical interference signal can be achieved under the influence of a modulating electrical signal and electrodes. Specifically, this involves suppressing or attenuating a comb-like pulse in the time domain of the optical interference signal.

[0035] Among them, the photodetector 4 converts the suppressed or attenuated optical interference signal into an electrical measurement signal that can be processed.

[0036] The signal processing circuit 5 acquires the electrical measurement signal and obtains the information carried by the signal through low-pass filtering, signal amplification, sampling detection, and demodulation. This information includes rotational information of the mechanical rotation and optical information of the optical interference signal before and after suppression or attenuation, such as frequency and amplitude. Based on the optical information, the signal processing circuit 5 can identify the rotation angle of the fiber optic gyroscope in inertial space and whether one or more time domains of the optical interference signal have comb-like pulse characteristics.

[0037] Simultaneously, before the LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator 3 participates in suppressing or attenuating the optical interference signal, the signal processing circuit 5 generates a square wave modulation signal based on the optical information. The square wave modulation signal modulates the waveform of the broadband optical signal propagating in the reverse direction within the fiber interferometer 2. The non-ideal nature of the square wave modulation signal is one of the possible factors causing comb-like pulses in the optical interference signal.

[0038] Therefore, the signal processing circuit 5 generates a modulation signal with a switching control timing of the modulated LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator 3 based on the optical information. The LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator 3, according to the timing control of the modulation signal, achieves time-domain suppression or attenuation of the comb-pulse characteristic portion in the optical interference signal.

[0039] Preferably, after effectively suppressing comb pulse errors in optical interference signals, broadband optical elements can increase optical power to improve the bandwidth of the fiber optic gyroscope, reduce output noise levels, and improve the temperature stability of the fiber optic gyroscope and suppress long-term drift.

[0040] Therefore, compared with the prior art, the embodiments of the present invention propose a scheme to suppress comb pulse error based on the LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator 3. It suppresses the error caused by comb pulse from the optical source of non-analog circuits, expands the effective sampling range of optical interference signals, suppresses the zero bias error caused by demodulation of electrical measurement signals, and makes the fiber optic gyroscope more adaptable to dynamic environments such as vibration and shock.

[0041] A second aspect of this invention discloses a comb pulse error suppression system for a fiber optic gyroscope. The suppression system is applied to the improvement of a fiber optic gyroscope. The fiber optic gyroscope includes a broadband light source 1, a fiber optic interferometer 2, and a photodetector 4. The suppression system includes an electro-optic intensity modulator 3 and a signal processing circuit 5.

[0042] A third aspect of this invention discloses a method for suppressing comb pulse errors in a fiber optic gyroscope. The suppression method is applied to the aforementioned fiber optic gyroscope. When implemented, the suppression method involves the following steps.

[0043] S10, the broadband light source 1 provides the fiber optic interferometer 2 with a broadband optical signal that meets the requirements of optical power, spectral shape, polarization characteristics and other indicators.

[0044] S20, the fiber optic interferometer 2 generates a first optical interference signal based on the forward and reverse propagation of the broadband optical signal and the mechanical rotation occurring in inertial space. At this time, the first optical interference signal is not modulated by a square wave and may not show comb pulses.

[0045] S30, the photodetector 4 generates a first electrical measurement signal based on the first optical interference signal.

[0046] S40, the signal processing circuit 5 analyzes the first electrical measurement signal after low-pass filtering, signal amplification, sampling detection, signal demodulation, and integration to obtain information such as the frequency and amplitude of the current first optical interference signal. The signal processing circuit 5 also analyzes the information from the first optical interference signal to obtain the broadband optical signal propagating backward within the long-wavelength modulated fiber optic interferometer 2.

[0047] S50, the fiber optic interferometer 2 generates a second optical interference signal with comb-like pulse characteristics based on a portion of the forward-propagating broadband optical signal, a portion of the backward-propagating broadband optical signal modulated by a square wave, and the mechanical rotation occurring in inertial space.

[0048] S60, the photodetector 4 generates a second electrical measurement signal based on the second optical interference signal with comb-like pulse characteristics.

[0049] S70, the signal processing circuit 5 analyzes the second electrical measurement signal after low-pass filtering, signal amplification, sampling detection, signal demodulation, and integration to obtain information such as the frequency and amplitude of the current second optical interference signal. Based on the information from the second optical interference signal, the signal processing circuit 5 generates a modulation signal for the LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator 3 to participate in the modulation of the optical interference signal. The modulation signal can modulate the switching control timing of the electrodes in the LiNbO3 waveguide-type Mach-Zehnder electro-optic intensity modulator 3.

[0050] S80, the electro-optic intensity modulator 3 suppresses or attenuates the time domain region where the comb pulse of the second optical interference signal is located according to the switching control timing of the modulation signal.

[0051] S90, photodetector 4 generates a third electrical measurement signal based on the suppressed second optical interference signal.

[0052] S100, the signal processing circuit 5 analyzes the current third optical interference signal after low-pass filtering, signal amplification, sampling detection, signal demodulation, and integration based on the third electrical measurement signal, obtaining information such as the frequency and amplitude of the current third optical interference signal. The signal processing circuit 5 also acquires rotational information of the mechanical rotation in inertial space based on the third electrical measurement signal and provides the output of the fiber optic gyroscope.

[0053] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0054] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0055] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An optical fiber gyroscope, characterized in that, the optical fiber gyroscope comprises a wide-spectrum light source, an optical fiber interferometer, an electro-optic intensity modulator, a photoelectric detector and a signal processing circuit; the wide-spectrum light source is configured to provide a wide-spectrum light signal to the optical fiber interferometer; the optical fiber interferometer is configured to generate at least one optical interference signal according to the wide-spectrum light signal and a mechanical rotation; the electro-optic intensity modulator is configured to suppress comb pulses of the optical interference signal according to at least one modulation signal; the photoelectric detector is configured to generate an electrical measurement signal according to the optical interference signal after the suppression; the signal processing circuit is configured to modulate a waveform of the wide-spectrum light signal propagating reversely in the optical fiber interferometer according to the electrical measurement signal, and to generate the modulation signal according to the electrical measurement signal; the signal processing circuit is configured to obtain rotation information of the mechanical rotation according to the electrical measurement signal.

2. The optical fiber gyroscope according to claim 1, characterized in that, the electro-optic intensity modulator is configured to suppress or attenuate a time domain part where the comb pulses of the optical interference signal are located according to the modulation signal.

3. The optical fiber gyroscope according to claim 2, characterized in that, the signal processing circuit is configured to generate the modulation signal which can modulate a switch control timing sequence of the electro-optic intensity modulator according to the electrical measurement signal.

4. The optical fiber gyroscope according to claim 1, characterized in that, the electro-optic intensity modulator is a LiNbO3 waveguide type Mach-Zehnder electro-optic intensity modulator.

5. The optical fiber gyroscope according to claim 1, characterized in that, the signal processing circuit is configured to generate a square wave modulation signal according to the electrical measurement signal and an optical path parameter of the optical fiber interferometer, and to modulate a waveform of the wide-spectrum light signal propagating reversely in the optical fiber interferometer according to the square wave modulation signal; the optical fiber interferometer is configured to generate the optical interference signal having the comb pulses according to a part of the wide-spectrum light signal propagating forwardly, a part of the wide-spectrum light signal propagating reversely after the modulation, and the mechanical rotation.

6. The optical fiber gyroscope according to claim 1, characterized in that, the signal processing circuit is configured to filter, amplify, sample and demodulate the electrical measurement signal.

7. The optical fiber gyroscope according to claim 1, characterized in that, the signal processing circuit is configured to drive the wide-spectrum light source to provide an output power of the wide-spectrum light signal according to the electrical measurement signal.

8. A fiber optic gyroscope comb pulse error suppression system, characterized by, application in an optical fiber gyroscope, the optical fiber gyroscope comprises a wide-spectrum light source, an optical fiber interferometer and a photoelectric detector; the suppression system comprises an electro-optic intensity modulator and a signal processing circuit; the wide-spectrum light source is configured to provide a wide-spectrum light signal to the optical fiber interferometer; the optical fiber interferometer is configured to generate at least one optical interference signal according to the wide-spectrum light signal and a mechanical rotation; the electro-optic intensity modulator is configured to suppress comb pulses of the optical interference signal according to at least one modulation signal; the photoelectric detector is configured to generate an electrical measurement signal according to the optical interference signal after the suppression; The signal processing circuit is configured to modulate a waveform of the broad spectrum light signal propagating reversely in the fiber interferometer according to the electrical measurement signal, and to generate the modulation signal according to the electrical measurement signal; The signal processing circuit is configured to acquire rotation information of the mechanical rotation according to the electrical measurement signal.

9. A method of fiber-optic gyroscope comb-spur error suppression, comprising: The application is applied to a fiber-optic gyroscope, which comprises a broad spectrum light source, a fiber interferometer, an electro-optical intensity modulator, a photoelectric detector and a signal processing circuit. The fiber-optic gyroscope comb pulse error suppression method comprises the following steps, The broad spectrum light source provides a broad spectrum light signal to the fiber interferometer; The fiber interferometer generates at least one first optical interference signal according to the mechanical rotation occurring in inertial space and the forward and reverse propagation of the broad spectrum light signal; The photoelectric detector generates a first electrical measurement signal according to the first optical interference signal; The signal processing circuit modulates the broad spectrum light signal propagating reversely in the fiber interferometer according to the first electrical measurement signal; The fiber interferometer generates a second optical interference signal with comb pulses according to the mechanical rotation and the forward propagation of a part of the broad spectrum light signal and the reverse propagation of a part of the broad spectrum light signal after modulation; The photoelectric detector generates a second electrical measurement signal according to the second optical interference signal with the comb pulses; The signal processing circuit generates a modulation signal according to the second electrical measurement signal; The electro-optical intensity modulator is configured to suppress the time domain of the comb pulses of the second optical interference signal according to the modulation signal.

10. The fiber-optic gyroscope comb pulse error suppression method according to claim 9, wherein, The photoelectric detector generates a third electrical measurement signal according to the second optical interference signal after suppression; The signal processing circuit acquires rotation information of the mechanical rotation according to the third electrical measurement signal.

Images