On-chip microcavity resonant optical gyroscope driven by broadband light source based on optical cancellation

Abstract

The invention discloses an on-chip micro-cavity resonant optical gyroscope driven by a broadband light source based on optical cancellation, and belongs to the field of gyroscope light path system design. The gyroscope comprises a broadband light source, a coupler, a first phase modulator, a second phase modulator, an echo wall mode optical microcavity, a photoelectric detector and a modulation-demodulation module. The first phase modulator inputs a first modulated optical signal from a third port of the coupler, the second phase modulator inputs a second modulated optical signal from a fourth port of the coupler, and the first modulated optical signal and the second modulated optical signal are split into two beams of optical signals with equal optical power in the coupler; and destructive interference occurs between one beam of light signal after beam splitting of the first modulated light signal and one beam of light signal after beam splitting of the second modulated light signal at a second port of the coupler, so that a light signal without a self-coherence component is obtained and output to the photoelectric detector. According to the invention, an optical cancellation method is adopted to eliminate self-coherence components which do not respond to rotation in the gyroscope, so that the signal-to-noise ratio is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of gyroscope optical path system design and weak signal detection technology, specifically relating to an on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical cancellation. Background Technology

[0002] An on-chip resonant optical gyroscope is a high-precision miniature inertial sensor that utilizes the optical Sagnac effect to detect angular velocity. It includes two main categories: on-chip waveguide resonant optical gyroscopes and on-chip microcavity resonant optical gyroscopes. On-chip waveguide resonant optical gyroscopes use an optical waveguide resonant cavity as their sensing element, while on-chip microcavity resonant optical gyroscopes use a whispering-gallery optical microcavity as their sensing element. Because whispering-gallery optical microcavities have lower transmission loss and more transmission modes, they can more effectively enhance the Sagnac effect, thus offering advantages in the miniaturization and integration of on-chip microcavity resonant optical gyroscopes.

[0003] On-chip microcavity resonant optical gyroscopes are further divided into two types: those driven by narrow-linewidth lasers and those driven by broadband light sources. Compared to traditional microcavity resonant optical gyroscopes driven by narrow-linewidth lasers, those driven by broadband light sources significantly reduce noise related to the coherence of the light source. However, in microcavity resonant optical gyroscopes driven by broadband light sources, the presence of self-coherent components in the detected signal that do not respond to rotation—which manifest as large-amplitude DC components—greatly limits the improvement of gyroscope sensitivity and noise suppression. This problem increases the difficulty of developing the microcavity resonant optical gyroscope market.

[0004] Furthermore, when integrating traditional broadband light source-driven microcavity resonant optical gyroscopes on a chip, an additional optical waveguide coupler is required to function as a circulator in the fiber optic system. This increases the overall loss and integration complexity of the on-chip system. The self-coherent component that does not respond to rotation manifests as a large-amplitude DC component in the signal to be detected, while the effective signal responding to rotation is a small-amplitude AC component. This places higher demands on the DC rejection ratio of the subsequent on-chip integrated photodetector, further increasing the difficulty of on-chip integration of broadband light source-driven microcavity resonant optical gyroscopes and hindering their expansion and application in the civilian market. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides an on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical destructive light.

[0006] The technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention discloses an on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical destructive, comprising a broadband light source, a coupler, a first phase modulator, a second phase modulator, a whispering-gallery-mode optical microcavity, a photodetector, a modulation / demodulation module, and a data logger; the first port of the coupler is connected to the broadband light source, the second port of the coupler is connected to the photodetector, the third port of the coupler is connected to one end of the first phase modulator, the fourth port of the coupler is connected to one end of the second phase modulator, and the other ends of the first and second phase modulators are connected to a pair of ports of the whispering-gallery-mode optical microcavity; the photodetector is connected to the modulation / demodulation module, the modulation / demodulation module generates a modulation signal and outputs it to the first and second phase modulators, the modulation / demodulation module demodulates the output of the photodetector and outputs the demodulated signal to the data logger as the gyroscope output of the on-chip microcavity resonant optical gyroscope;

[0008] In this system, the first phase modulator receives the first modulated optical signal from the third port of the coupler, and the second phase modulator receives the second modulated optical signal from the fourth port of the coupler. Both the first and second modulated optical signals are split into two optical signals with equal optical power at the coupler. The optical signal after the first modulated optical signal is split into two optical signals after the second modulated optical signal is split into two optical signals, which undergo destructive interference at the second port of the coupler, resulting in an optical signal without self-coherent components, which is then output to the photodetector.

[0009] Secondly, a method for detecting the angular velocity of a motion system based on the on-chip microcavity resonant optical gyroscope includes the following steps:

[0010] The on-chip microcavity resonant optical gyroscope is mounted on a motion system for detecting angular velocity; wherein the motion system includes a drone, spacecraft, or robot.

[0011] A broadband light source outputs broadband light to the first port of a coupler. The broadband light is split into two optical signals with equal power at the coupler. One optical signal enters the first phase modulator through the third port of the coupler, and the other optical signal enters the second phase modulator through the fourth port of the coupler. The two phase modulators couple their modulated optical signals into a whispering-gallery mode optical microcavity through their corresponding ports. Both optical signals are transmitted in the microcavity in multiple optical modes. After transmission, they are coupled to their corresponding ports and then output to the first and second phase modulators. The first phase modulator outputs a first modulated optical signal to the third port of the coupler, and the second phase modulator outputs a second modulated optical signal to the fourth port of the coupler. The first and second modulated optical signals are split into two optical signals with equal power at the coupler. The optical signal after the first modulated optical signal is split into two optical signals with equal power and the optical signal after the second modulated optical signal is split into two optical signals at the second port of the coupler. The resulting optical signal without self-coherent components is output to a photodetector for photoelectric conversion. The photodetector outputs an electrical signal to the modulation and demodulation module.

[0012] The modulation and demodulation module generates a modulation signal and outputs it to the first phase modulator and the second phase modulator. The first phase modulator and the second phase modulator perform phase modulation on the optical signal passing through them according to the modulation signal. The modulation and demodulation module demodulates the electrical signal output by the photodetector to obtain a demodulated signal, and outputs the demodulated signal to the data logger as the gyroscope output of the on-chip microcavity resonant optical gyroscope. Finally, the angular velocity of the motion system is obtained from the gyroscope output.

[0013] Furthermore, the phase difference between the optical signal entering the second phase modulator via the fourth port of the coupler and the optical signal entering the first phase modulator via the third port of the coupler is π / 2.

[0014] Furthermore, the optical signal output from the first phase modulator to the whispering-gallery mode optical microcavity is output to the second phase modulator after completing multimode transmission; the optical signal output from the second phase modulator to the whispering-gallery mode optical microcavity is output to the first phase modulator after completing multimode transmission.

[0015] Furthermore, the phase difference between the optical signal transmitted to the second port of the coupler after the first modulated optical signal is split and the optical signal transmitted to the second port of the coupler after the second modulated optical signal is split is π.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. The present invention provides an on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical cancellation and its detection method. By utilizing the optical cancellation method, the operating point of the interference light carrying rotation information is shifted from the interference peak to the interference valley of the microcavity resonant optical gyroscope driven by a traditional broadband light source. This eliminates the self-coherent DC component in the output signal to be detected by the on-chip microcavity resonant optical gyroscope that does not respond to rotation, greatly reducing the noise positively correlated with optical power in the on-chip microcavity resonant optical gyroscope, including relative intensity noise and shot noise, improving the signal-to-noise ratio of the gyroscope, and ultimately achieving a significant improvement in the gyroscope detection accuracy.

[0018] 2. The on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical cancellation provided by this invention reduces the number of optical components, allowing the optical system of the on-chip microcavity resonant optical gyroscope to be integrated onto the same silicon substrate using a monolithic integration approach, thereby significantly reducing the size of the on-chip microcavity resonant optical gyroscope. Furthermore, since the DC component in the signal to be detected is eliminated through optical cancellation, the requirement for the DC suppression ratio of the on-chip photodetector is reduced, all of which contribute to the miniaturization of the angular velocity detection system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical cancellation according to the present invention;

[0020] Figure 2 This is the transmission spectrum of a whispering-gallery mode optical microcavity with multimode transmission;

[0021] Figure 3 This is the reflection spectrum of a whispering-gallery mode optical microcavity with multimode transmission;

[0022] Figure 4 It is a schematic diagram of the curves showing the relationship between the magnitude of the detected optical power and the resonant frequency difference caused by the rotation;

[0023] Figure 5 This is a schematic diagram of a specific implementation case of an on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical destructive.

[0024] In the figure: 1. Silicon substrate, 2. Broadband light source, 3. 2×2 3dB directional coupler, 4. First phase modulator, 5. Second phase modulator, 6. Whispering-gallery mode optical microcavity, 7. Photodetector, 8. Signal modulation and demodulation module, 9. Data logger. Detailed Implementation

[0025] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0026] To address the shortcomings of existing technologies, this invention aims to propose an on-chip microcavity resonant optical gyroscope system that utilizes a 2×2 3dB optical waveguide coupler. During transmission, an inherent π / 2 phase difference exists between the through-end and cross-end of the coupler. This allows the clockwise and counterclockwise optical signals passing through the coupler twice, due to their different transmission paths, to automatically acquire a π phase difference during interference, thereby achieving optical destructive phase. The 2×2 3dB optical waveguide coupler can be a directional coupler structure or a multimode interference coupler structure; for simplicity, the following explanation will only use a 2×2 3dB directional coupler as an example.

[0027] like Figure 1 and Figure 5 As shown, this is the structure of an on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical destructive propagation provided in this embodiment. The on-chip microcavity resonant optical gyroscope includes an optical system, a signal processing system, and a data logger 9. The optical system includes a broadband light source 2, a photodetector 7, a 2×2 3dB directional coupler 3, a first phase modulator 4, a second phase modulator 5, and a whispering-gallery mode optical microcavity 6. The signal processing system consists of a signal modulation and demodulation module 8. The broadband light source 2, the 2×2 3dB directional coupler 3, the first phase modulator 4, the second phase modulator 5, the whispering-gallery mode optical microcavity 6, and the photodetector 7 are heterogeneously integrated on the same silicon substrate 1 using die-to-wafer bonding technology.

[0028] The broadband light source 2 is connected to the first port of the 2×2 3dB directional coupler 3. The third port of the 2×2 3dB directional coupler 3 is connected to one end of the first phase modulator 4 and one end of the second phase modulator 5. The other ends of the first phase modulator 4 and the second phase modulator 5 are connected to a pair of ports of the whispering-gallery mode optical microcavity 6, wherein the pair of ports of the whispering-gallery mode optical microcavity is a pair of transmission ports or a pair of reflection ports. The second port of the 2×2 3dB directional coupler 3 is connected to the input of the photodetector 7. The output of the photodetector 7 is connected to the input of the modulation and demodulation module 8. The modulation and demodulation module 8 generates a modulation signal and outputs it to the first phase modulator 4 and the second phase modulator 5. The modulation and demodulation module 8 demodulates the output of the photodetector 7 and outputs the demodulated signal to the data logger 9 as the gyroscope output of the on-chip microcavity resonant optical gyroscope.

[0029] The modulation signals output by the modulation and demodulation module to the first phase modulator and the second phase modulator have the same frequency, the same amplitude, and a phase difference of π, and both modulation signals are sinusoidal signals.

[0030] In a specific embodiment of the present invention, the method for detecting the angular velocity of a motion system based on the on-chip microcavity resonant optical gyroscope includes the following steps:

[0031] (1) The broadband light source 2, photodetector 7, 2×2 3dB directional coupler 3, two phase modulators and whispering-gallery mode optical microcavity 6 are heterogeneously integrated on the same silicon substrate 1 by Die to Wafer bonding technology;

[0032] (2) The on-chip microcavity resonant optical gyroscope is mounted on a motion system for angular velocity detection; wherein the motion system can be a drone, a spacecraft or a robot.

[0033] The broadband light source 2 outputs broadband light to the first port of the 2×2 3dB directional coupler 3. The broadband light is split into two optical signals with equal optical power in the 2×2 3dB directional coupler 3. The first optical signal enters the first phase modulator 4 through the third port of the 2×2 3dB directional coupler 3, and the second optical signal enters the second phase modulator 5 through the fourth port of the 2×2 3dB directional coupler 3. The first phase modulator 4 and the second phase modulator 5 couple the modulated optical signals into the whispering-gallery mode optical microcavity through a pair of ports. That is, after the broadband light emitted by the broadband light source 2 is split by the 2×2 3dB directional coupler 3, it enters the whispering-gallery mode optical microcavity 6 through the first phase modulator 4 and the second phase modulator 5 respectively, and in clockwise and counterclockwise directions. Then, the two optical signals are transmitted in multiple turns within the whispering-gallery mode optical microcavity 6. Afterward, the clockwise and counterclockwise beams pass through the second phase modulator 5 and the first phase modulator 4 respectively, and are combined and interfered within the 2×2 3dB directional coupler 3. That is, both optical signals are transmitted in multiple optical modes within the whispering-gallery mode optical microcavity 6. After being transmitted through each optical mode, the two optical signals are coupled to corresponding ports within the whispering-gallery mode optical microcavity 6. The two optical signals after multimode transmission are output to the first phase modulator 4 and the second phase modulator 5 respectively through the corresponding ports. That is, the optical signal output from the first phase modulator 4 to the whispering-gallery mode optical microcavity 6 is output to the second phase modulator 5 after completing multimode transmission; the optical signal output from the second phase modulator 5 to the whispering-gallery mode optical microcavity 6 is output to the first phase modulator 4 after completing multimode transmission.

[0034] The first phase modulator 4 outputs a first modulated optical signal to the third port of the 2×2 3dB directional coupler 3, and the second phase modulator 5 outputs a second modulated optical signal to the fourth port of the 2×2 3dB directional coupler 3. Both the first and second modulated optical signals are split into two optical signals with equal optical power at the 2×2 3dB directional coupler 3. The optical signal after the first modulated optical signal is split and the optical signal after the second modulated optical signal is split undergo destructive interference at the second port of the 2×2 3dB directional coupler 3, resulting in an optical signal without self-coherent components.

[0035] Due to the inherent π / 2 phase difference between the through end and the cross end of the 2×2 3dB directional coupler 3, after the first optical signal is transmitted in the whispering-gallery mode optical microcavity 6, it becomes a second modulated optical signal and enters the 2×2 3dB directional coupler 3 through the fourth port. Then, the second modulated optical signal is split, and one of the optical signals is output to the second port of the 2×2 3dB directional coupler 3. Therefore, the first optical signal passes through the through end of the 2×2 3dB directional coupler 3 twice during the entire transmission process.

[0036] After the second optical signal is transmitted in the whispering-gallery mode optical microcavity 6, it becomes the first modulated optical signal and enters the 2×2 3dB directional coupler 3 through the third port of the 2×2 3dB directional coupler 3. Then the first modulated optical signal is split, and one of the optical signals is output to the second port of the 2×2 3dB directional coupler 3. Therefore, the second optical signal passes through the cross-end of the 2×2 3dB directional coupler 3 twice during the entire transmission process.

[0037] Therefore, when the first optical signal and the second optical signal are combined and coherent at the second port of the 2×2 3dB directional coupler 3, there will be a phase difference of π between the two beams, resulting in destructive interference, and an optical signal without self-coherent components is obtained and output to the photodetector.

[0038] In this embodiment, the first optical signal passes through the direct-through end of the 2×2 3dB coupler 3 twice during its entire transmission process, entering from the first port and exiting from the third port, and from the fourth port and exiting from the second port, respectively. The second optical signal passes through the cross-through end of the 2×2 3dB coupler 3 twice during its entire transmission process, entering from the first port and exiting from the fourth port, and from the third port and exiting from the second port, respectively. Because of the inherent π / 2 phase difference between the direct-through end and the cross-through end of the 2×2 3dB directional coupler 3, and because the two optical signals pass through both the direct-through end and the cross-through end, when the two signal beams are combined and coherent at the second port of the 2×2 3dB coupler 3, an inherent π phase difference exists, resulting in destructive interference.

[0039] The intensity of light obtained after the interference of two signal beams is determined by the square of the sum of the complex amplitudes of the two beams. This operation is equivalent to the product of the complex amplitudes of the two beams and their conjugates. The result consists of four components: the first two terms are the product of the light fields of the two beams and their conjugates, which is the self-coherent component, the intensity of which depends only on the intensity of each beam itself; the last two terms are the product of the light field of one beam and the conjugate of the other beam, which is the cross-correlation component, the intensity of which is determined by the amplitude, frequency, and phase difference of the two beams. If the two beams have the same frequency, equal amplitude, and the same phase, the cross-correlation term and the self-coherent term are equal in value and have the same sign, and the final light intensity is the sum of the two, exhibiting constructive interference, with the light intensity reaching its maximum value. Conversely, if the two beams have the same frequency and amplitude but a phase difference of π, the cross-correlation term and the self-coherent term are equal in value but opposite in sign, canceling each other out, and the self-coherent component is eliminated, resulting in a final light intensity close to zero, i.e., destructive interference. In this on-chip microcavity resonant optical gyroscope, when the gyroscope system is stationary, the clockwise and counterclockwise signal light fields have the same frequency and amplitude, but a phase difference of π, thus resulting in destructive coherence. When the gyroscope system rotates, a frequency difference is generated between the clockwise and counterclockwise signal lights due to the Sagnac effect. The intensity of the self-coherent part remains unchanged, while the intensity of the mutually coherent part decreases, so the total light intensity detected after interference increases.

[0040] (3) Signal modulation:

[0041] The optical signal without self-coherent components is output to the photodetector 7 for photoelectric conversion. The photodetector 7 outputs an electrical signal to the modulation and demodulation module 8. The modulation and demodulation module 8 generates a modulation signal and outputs it to the first phase modulator 4 and the second phase modulator 5. The first phase modulator 4 and the second phase modulator 5 perform phase modulation on the optical signal passing through them according to the modulation signal.

[0042] The low-coherence light emitted by the broadband light source 2 is split by the 2×2 3dB directional coupler 3 and then phase-modulated at the first phase modulator 4 and the second phase modulator 5, respectively. The driving signals of the two phase modulators are the modulation signals U1(t) and U2(t) generated by the modulation and demodulation module 8. U1(t) and U2(t) are sinusoidal signals with the same frequency, the same amplitude, and a phase difference of π.

[0043] (4) Signal demodulation:

[0044] The modulation and demodulation module 8 demodulates the electrical signal output by the photodetector 7 to obtain a demodulated signal.

[0045] The interference signal (optical signal without self-coherent components) generated at the 2×2 3dB directional coupler 3 enters the photodetector 7 and is converted into an electrical signal. The modulation and demodulation module 8 generates a reference signal with the same frequency as the modulation signal U1(t) to demodulate the electrical signal.

[0046] (5) Signal output and angular velocity calculation:

[0047] The modulation and demodulation module 8 outputs the demodulated signal to the data logger 9 as the gyroscope output of the on-chip microcavity resonant optical gyroscope; finally, the angular velocity of the motion system is obtained based on the gyroscope output.

[0048] When the on-chip microcavity resonant optical gyroscope is stationary, the intensity of the interference beam at the second port of the 2×2 3dB directional coupler 3 reaches its maximum value. When the on-chip microcavity resonant optical gyroscope rotates, the intensity of the interference beam changes with the rotation speed. Therefore, the angular velocity can be detected by detecting the change in the power of the interference signal. The demodulation output of the modulation and demodulation module 8 reflects the change in optical power. Therefore, the demodulation output of the modulation and demodulation module 8 is used as the output of the on-chip microcavity resonant optical gyroscope and output to the data logger 9. Finally, after calibration, the angular velocity detection value of the on-chip microcavity resonant optical gyroscope can be obtained.

[0049] like Figure 2 As shown, the transmission spectrum of the whispering-gallery mode optical microcavity 6 used in the implementation case is given. It can be seen that under the condition of having an extremely high quality factor, the microcavity also supports multimode transmission, which can improve the amplitude of the system's detection signal.

[0050] like Figure 3 As shown, the reflection spectrum of the whispering-gallery mode optical microcavity 6 used in the implementation case is presented. For a traditional microcavity resonant optical gyroscope system driven by a broadband light source, since the overall intensity of the reflected spectrum is much greater than that of the transmitted spectrum, and the autocorrelation component in the coherent intensity is only related to the intensity of the signal light itself, and the effective signal magnitude responding to rotation does not increase, the autocorrelation component in the probe intensity that does not respond to rotation will completely consume the effective signal, resulting in a very poor signal-to-noise ratio. However, after using the optical cancellation scheme, the autocorrelation component can be completely eliminated, so it can be used at the transmission end of the whispering-gallery mode optical microcavity. Generally, if a pair of transmission ports of a whispering-gallery mode optical microcavity is used, only one coupling is required, while if a pair of reflection ports of a whispering-gallery mode optical microcavity is used, two couplings are required. This advantage of the scheme also helps in the integration and miniaturization of the on-chip system.

[0051] like Figure 4The diagram shows a schematic of the probe optical power versus the resonant frequency difference caused by rotation. The probe optical power curve shows that when the on-chip microcavity resonant optical gyroscope is stationary, the probe optical power has a minimum value, close to 0. When the on-chip microcavity resonant optical gyroscope rotates, the probe optical power increases. This means that the probe optical power output by the on-chip microcavity resonant optical gyroscope is entirely related to rotation, and the portion that does not respond to rotation has been completely canceled out.

[0052] like Figure 5 As shown, this is an implementation example of an on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical destructive propagation. The on-chip microcavity resonant optical gyroscope includes a broadband light source 2, a 2×2 3dB directional coupler 3, a first phase modulator 4, a second phase modulator 5, a whispering-gallery mode optical microcavity 6, a photodetector 7, a signal modulation and demodulation module 8, and a data logger 9. The broadband light source 2, the 2×2 3dB directional coupler 3, the first phase modulator 4, the second phase modulator 5, the whispering-gallery mode optical microcavity 6, and the photodetector 7 are heterogeneously integrated on the same silicon substrate 1 using die-to-wafer bonding technology.

[0053] The on-chip microcavity resonant optical gyroscope is mounted on a motion system for angular velocity detection. The light emitted from the broadband light source 2 is split by the 2×2 3dB directional coupler 3, and then passes through the first phase modulator 4 and the second phase modulator 5 respectively, entering the whispering-gallery mode optical microcavity 6 in clockwise and counterclockwise directions. It undergoes multiple turns of transmission within the whispering-gallery mode optical microcavity 6. Afterward, the clockwise and counterclockwise beams pass through the first phase modulator 4 and the second phase modulator 5 again, and are combined and interfered within the 2×2 3dB directional coupler 3. Because the propagation paths of the clockwise and counterclockwise beams differ, the clockwise beam passes through the straight-through end of the 2×2 3dB directional coupler 3 twice, while the counterclockwise beam passes through the cross end of the 2×2 3dB directional coupler 3 twice. Since there is an inherent propagation phase difference of π / 2 between the straight-through and cross ends of the 2×2 3dB directional coupler 3, the two beams exhibit an inherent phase difference of π, resulting in destructive interference. The self-coherent components that do not respond to rotation are subtracted from each other. Finally, the beam obtained from the interference passes through the 2×2 3dB directional coupler 3 and enters the photodetector 6, where it is converted into an electrical signal. This signal is then demodulated to become the gyroscope output of the on-chip microcavity resonant optical gyroscope. Finally, the angular velocity of the motion system is obtained from the gyroscope output.

[0054] This invention employs an optical cancellation method to eliminate the non-rotational self-coherent components in an on-chip microcavity resonant optical gyroscope. Without affecting the effective signal amplitude in the detected optical signal, it significantly reduces the unwanted DC component, ensuring that all probe light power in the on-chip microcavity resonant optical gyroscope is a detectable effective signal. This reduces noise related to probe light power magnitude, including relative intensity noise and shot noise, improving the sensitivity of angular rate detection and effectively increasing the system's signal-to-noise ratio. Simultaneously, it reduces the number of optical components and adopts a monolithic integration approach, greatly reducing the system's size and aligning with the trend towards miniaturization.

[0055] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An on-chip microcavity resonant optical gyroscope driven by a broadband light source based on optical destructive light, characterized in that, It includes a broadband light source, a coupler, a first phase modulator, a second phase modulator, a whispering-gallery mode optical microcavity, a photodetector, a modulation and demodulation module, and a data logger; The first port of the coupler is connected to a broadband light source, the second port of the coupler is connected to a photodetector, the third port of the coupler is connected to one end of the first phase modulator, the fourth port of the coupler is connected to one end of the second phase modulator, and the other ends of the first and second phase modulators are connected to a pair of ports of the whispering-gallery mode optical microcavity. The photodetector is connected to the modulation and demodulation module. The modulation and demodulation module generates a modulation signal and outputs it to the first phase modulator and the second phase modulator. The modulation and demodulation module demodulates the output of the photodetector and outputs the demodulated signal to the data logger as the gyroscope output of the on-chip microcavity resonant optical gyroscope. In this system, the first phase modulator receives the first modulated optical signal from the third port of the coupler, and the second phase modulator receives the second modulated optical signal from the fourth port of the coupler. Both the first and second modulated optical signals are split into two optical signals with equal optical power at the coupler. The optical signal after the first modulated optical signal is split into two optical signals after the second modulated optical signal is split into two optical signals, which undergo destructive interference at the second port of the coupler, resulting in an optical signal without self-coherent components, which is then output to the photodetector.

2. The on-chip microcavity resonant optical gyroscope according to claim 1, characterized in that, The pair of ports of the whispering-gallery mode optical microcavity is either a pair of transmissive ports or a pair of reflective ports. The coupler is a 2×2 3dB optical waveguide coupler, which adopts a directional coupler structure or a multimode interference coupler structure.

3. The on-chip microcavity resonant optical gyroscope according to claim 1, characterized in that, The modulation signals output by the modulation and demodulation module to the first phase modulator and the second phase modulator have the same frequency, the same amplitude, and a phase difference of π, and both modulation signals are sinusoidal signals.

4. A method for detecting the angular velocity of a motion system based on the on-chip microcavity resonant optical gyroscope of claim 1, characterized in that, Includes the following steps: The on-chip microcavity resonant optical gyroscope is mounted on a motion system for angular velocity detection. A broadband light source outputs broadband light to the first port of a coupler. The broadband light is split into two optical signals with equal power at the coupler. One optical signal enters the first phase modulator through the third port of the coupler, and the other optical signal enters the second phase modulator through the fourth port of the coupler. The two phase modulators couple their modulated optical signals into a whispering-gallery mode optical microcavity through their corresponding ports. Both optical signals are transmitted in the microcavity in multiple optical modes. After transmission, they are coupled to their corresponding ports and then output to the first and second phase modulators. The first phase modulator outputs a first modulated optical signal to the third port of the coupler, and the second phase modulator outputs a second modulated optical signal to the fourth port of the coupler. The first and second modulated optical signals are split into two optical signals with equal power at the coupler. The optical signal after the first modulated optical signal is split into two optical signals with equal power and the optical signal after the second modulated optical signal is split into two optical signals at the second port of the coupler. The resulting optical signal without self-coherent components is output to a photodetector for photoelectric conversion. The photodetector outputs an electrical signal to the modulation and demodulation module. The modulation and demodulation module generates a modulation signal and outputs it to the first phase modulator and the second phase modulator. The first phase modulator and the second phase modulator perform phase modulation on the optical signal passing through them according to the modulation signal. The modulation and demodulation module demodulates the electrical signal output by the photodetector to obtain a demodulated signal, and outputs the demodulated signal to the data logger as the gyroscope output of the on-chip microcavity resonant optical gyroscope; finally, the angular velocity of the motion system is obtained based on the gyroscope output.

5. The method for detecting the angular velocity of a motion system according to claim 4, characterized in that, The phase difference between the optical signal entering the second phase modulator via the fourth port of the coupler and the optical signal entering the first phase modulator via the third port of the coupler is π / 2.

6. The method for detecting the angular velocity of a motion system according to claim 4, characterized in that, The optical signal output from the first phase modulator to the whispering-gallery mode optical microcavity is then output to the second phase modulator after completing multimode transmission. The optical signal output from the second phase modulator to the whispering-gallery mode optical microcavity is then output to the first phase modulator after completing multimode transmission.

7. The method for detecting the angular velocity of a motion system according to claim 4, characterized in that, The phase difference between the optical signal transmitted to the second port of the coupler after the first modulated optical signal is split and the optical signal transmitted to the second port of the coupler after the second modulated optical signal is split is π.

8. The method for detecting the angular velocity of a motion system according to claim 4, characterized in that, The modulation and demodulation module generates a reference signal with the same frequency as the modulation signal to demodulate the electrical signal output by the photodetector.

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