Optical transceiver chip for interferometric fiber-optic gyroscope and interferometric fiber-optic gyroscope

Abstract

The present disclosure provides an optical transceiver chip for an interferometric fiber-optic gyroscope and an interferometric fiber-optic gyroscope. The optical transceiver chip comprises: an on-chip micro-ring resonator comprising a nonlinear medium and configured to be able to couple to a pump light source and receive a pump light signal from the pump light source, and based on a third-order nonlinear effect of the nonlinear medium, generate a non-coherent wide-spectrum optical frequency comb signal from the pump light signal; a fiber coupling device configured to be coupled to the on-chip micro-ring resonator and receive the non-coherent wide-spectrum optical frequency comb signal, the fiber coupling device is further configured to be able to couple to a sensing fiber of the interferometric fiber-optic gyroscope, and provide the non-coherent wide-spectrum optical frequency comb signal to the sensing fiber of the interferometric fiber-optic gyroscope and receive a return light signal from the sensing fiber; and a photoelectric detection device configured to be coupled to the fiber coupling device, receive the return light signal and detect an interference light signal based on interference between the return light signals.

Description

Technical Field

[0001] This disclosure relates to optical transceiver chips for use in interferometric fiber optic gyroscopes and fiber optic gyroscopes. Background Technology

[0002] As a completely solid-state instrument, fiber optic gyroscopes have no moving or wearing parts, and therefore offer advantages such as low cost, long lifespan, wide application coverage, resistance to electromagnetic interference, and no drift caused by acceleration. Consequently, fiber optic gyroscopes are gradually replacing traditional electromechanical gyroscopes and expensive laser gyroscopes, becoming the mainstream solution in gyroscope manufacturing.

[0003] Currently, fiber optic gyroscopes are trending towards miniaturization and integration. Furthermore, to improve the accuracy of fiber optic gyroscopes, higher power requirements are being placed on the light source. To address this trend, it is necessary to provide a miniaturized, integrated, and high-power light source system for fiber optic gyroscopes. Summary of the Invention

[0004] This invention provides an optical transceiver chip for an interferometric fiber optic gyroscope and an interferometric fiber optic gyroscope, which can achieve miniaturization and integration and have high power.

[0005] One aspect of the present invention relates to an optical transceiver chip for an interferometric fiber optic gyroscope, comprising: an on-chip microring resonator including a nonlinear medium and configured to be coupled to and receive a pump light signal from the pump light source, and to generate an incoherent broadband optical frequency comb signal from the pump light signal based on a third-order nonlinear effect of the nonlinear medium; an optical fiber coupling device configured to be coupled to the on-chip microring resonator and receive the incoherent broadband optical frequency comb signal, the optical fiber coupling device further configured to be coupled to a sensing fiber of the interferometric fiber optic gyroscope, and to provide the incoherent broadband optical frequency comb signal to the sensing fiber of the interferometric fiber optic gyroscope and receive a return optical signal from the sensing fiber; and a photodetector configured to be coupled to the optical fiber coupling device, receive the return optical signal, and detect an interference optical signal based on the interference between the return optical signals.

[0006] Another aspect of this disclosure relates to an interferometric fiber optic gyroscope, comprising an optical transceiver chip as described above and a sensing fiber optic cable. Attached Figure Description

[0007] The above and other objects and advantages of this disclosure will be further described below with reference to specific embodiments and the accompanying drawings. In the drawings, the same or corresponding technical features or components will be represented by the same or corresponding reference numerals.

[0008] Figure 1 A schematic diagram of the composition of a fiber optic gyroscope according to an embodiment of the present disclosure is shown.

[0009] Figure 2 This is a real-time graph of a broadband incoherent optical frequency comb signal generated according to embodiments of the present disclosure.

[0010] Figure 3 It is an average time integral plot of a broadband incoherent optical frequency comb signal generated according to embodiments of the present disclosure. Detailed Implementation

[0011] The following detailed description is based on the accompanying drawings and provides various exemplary embodiments of the present disclosure to aid in a comprehensive understanding. Various details are included in the following description to aid understanding; however, these details are considered exemplary only and not intended to limit the present disclosure, which is defined by the appended claims and their equivalents. The words and phrases used in the following description are intended only to provide a clear and consistent understanding of the present disclosure. Additionally, descriptions of well-known structures, functions, and configurations may have been omitted for clarity and brevity. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the scope of the present disclosure.

[0012] In integrated fiber optic gyroscope systems based on related technologies, amplified spontaneous emission (ASE) or superluminescent light-emitting diode (SLD) sources are commonly used. However, ASE sources require external erbium-doped fiber, wavelength division multiplexer (WDM), mirrors, fiber optic filters, and other components, making the system relatively complex and hindering miniaturization and integration. Furthermore, SLD sources have low power, typically only 2mW, resulting in a low signal-to-noise ratio, which is detrimental to improving the accuracy of fiber optic gyroscopes.

[0013] Figure 1 This is a schematic diagram of an optical transceiver chip for an interferometric fiber optic gyroscope according to an embodiment of the present disclosure.

[0014] like Figure 1 As shown, the optical transceiver chip 100 according to this embodiment includes an on-chip microring resonator 23. The microring resonator 23 typically includes a straight waveguide and a microring resonant cavity coupled to each other. The radius of the microring resonant cavity is typically on the order of several micrometers to several hundred micrometers. Pump light propagating in the straight waveguide, after being coupled into the microring resonant cavity, can propagate around the microring within the cavity, maintaining a high optical power density due to constructive interference. Therefore, the microring resonator 23 can have a high quality factor (Q value). The quality factor of the microring resonant cavity is a parameter used to measure the ability of the microcavity to store optical signal energy / power, and can be expressed as the ratio of the energy / power of the optical signal within the cavity to the energy / power attenuation rate. In embodiments of this disclosure, the quality factor of the microring resonator 23 can have 10. 5 Up to 10 9 The magnitude.

[0015] In embodiments of this disclosure, the on-chip microring resonator 23 includes a nonlinear medium exhibiting a third-order nonlinear effect. This third-order nonlinear effect, also known as the optical Kerr effect, originates from nonlinear polarization within the medium, which in turn alters the transmission properties of light. In this optical effect, the electric field of the light wave itself causes a change in refractive index, the magnitude of which is related to the local intensity of the light wave. The change in refractive index of the medium due to the electric field further promotes nonlinear optical effects such as self-phase modulation, cross-phase modulation, four-wave mixing, and modulation instability. These nonlinear optical effects are all encompassed within the third-order nonlinear effect of this disclosure.

[0016] Self-phase modulation (SPM) refers to the following effect: In a nonlinear optical medium, the intensity of incident light causes a change in the effective refractive index of the medium, and the amount of change is proportional to the light intensity. This change in effective refractive index, in turn, affects the subsequent incident light field, causing nonlinear phase modulation and resulting in a phase change. The phase change induced by SPM in a microring resonator broadens the spectrum.

[0017] The cross-phase modulation effect refers to the following effect: In a nonlinear optical medium, not only does the intensity of incident light cause a change in the effective refractive index of the medium, but the effective refractive index is also affected by the intensity of other light transmitted at the same time, thereby producing a nonlinear phase shift.

[0018] Four-wave mixing refers to the redistribution of energy between light waves of at least two frequencies that satisfy the phase-matching condition in a nonlinear medium. Four-wave mixing can occur when light with at least two different frequency components propagates simultaneously in a nonlinear medium. Assuming the input light has two frequency components v1 and v2 (let v2 > v1), if the phase-matching condition (simultaneously satisfying energy and momentum conservation) is met, two new frequency components will be generated: v3 = v1 - (v2 - v1) = 2v1 - v2 and v4 = v2 + (v2 - v1) = 2v2 - v1. If v3 or v4 already existed, then v3 or v4 is amplified, meaning these two frequency components undergo parametric amplification.

[0019] Four-wave mixing in optical fibers is closely related to self-phase modulation and cross-phase modulation. These effects are caused by the same nonlinear effect (Kerr effect), except that the frequency degeneracy of light differs in each effect.

[0020] The modulation instability effect refers to the following: Many nonlinear systems exhibit an instability caused by the interaction between nonlinearity and dispersion effects, resulting in modulation of the steady state. Continuous or quasi-continuous waves generate self-modulation of amplitude and frequency through a nonlinear dispersive medium, causing the perturbations superimposed on the continuous or quasi-continuous wave to grow exponentially.

[0021] Modulation instability typically occurs only under certain conditions, usually under anomalous dispersion (negative dispersion), i.e., shorter wavelengths exhibit greater group velocity dispersion. Since optical power density is highly dependent on frequency perturbations, these perturbations are very weak at a specific frequency. However, at other frequencies, the perturbations grow exponentially. Random perturbations generate frequencies containing a large number of frequency components, with the frequency possessing the highest gain and satisfying the microcavity resonance condition becoming the first pair of newly generated frequency sidebands. Modulation instability is related to material dispersion, optical propagation distance, and optical power, and is often considered a special type of four-wave mixing phenomenon affecting the signal-to-noise ratio.

[0022] In nonlinear media, four-wave mixing, cascaded four-wave mixing, and modulation instability primarily lead to the generation of multiple frequencies, resulting in spectral broadening. Self-phase modulation and cross-phase modulation continuously affect the phase of optical frequencies, while also promoting spectral broadening.

[0023] In embodiments of this disclosure, such as Figure 1 As shown, the on-chip microring resonator 23 is configured to couple to and receive pump light signals from the pump light source 1. Based on the third-order nonlinear effect of the nonlinear medium on the pump light, the on-chip microring resonator 23 can generate incoherent optical frequency comb signals.

[0024] During the injection of pump light into the microring resonator, different third-order nonlinear effects interact and influence each other, ultimately leading to the generation of a stable optical frequency comb based on the pump light signal. An optical frequency comb, also called an optical frequency comb, refers to an optical signal formed by equally spaced ultrashort pulses at a given frequency, whose spectrum resembles the "teeth" of a comb. There are various mechanisms for generating optical frequency combs; this disclosure focuses on the mechanism of generating an optical frequency comb through the nonlinear effects of the nonlinear medium in the microring resonator.

[0025] The initial stage of optical frequency comb generation based on nonlinear effects can be described using four-wave mixing theory. As the pump light tunes towards the resonant wavelength, it provides parametric gain to the resonant cavity, causing new frequency components to be generated at other resonant wavelengths. Subsequently, through continuous tuning, cascaded four-wave mixing occurs, leading to modulation instability, during which noise is amplified. In the process of generating optical frequency combs based on third-order nonlinear effects, noise signals are generated between the optical frequency combs due to modulation instability effects, and these noise signals are also amplified. Furthermore, the resulting optical frequency combs are incoherent.

[0026] To achieve a significant four-wave mixing effect, the frequency components propagating in the on-chip microring resonator 23 need to satisfy the phase-matching condition, i.e., the phase mismatch should be almost zero. There are three main causes of phase mismatch: material dispersion, waveguide dispersion, and nonlinear effects. Generally, material dispersion is determined by the material and is a fixed value for each resonator. Phase mismatch caused by nonlinear effects is positive. Besides compensating for the phase mismatch caused by nonlinear effects by directing the pump light into an anomalous dispersion region close to zero, waveguide dispersion can also be altered by designing different waveguide structures. Ultimately, reducing the overall phase mismatch value results in a better dispersion curve, allowing the four-wave mixing effect to occur better within the required range, leading to better optical frequency comb output.

[0027] The dispersion curve of a microring resonator can be determined by designing the waveguide structure of the resonator. For example, by changing the width and height of the cross-section of the microring resonator, the dispersion curve can be adjusted to achieve a desired shape. Specifically, the on-chip microring resonator 23 is made to have a desired negative dispersion coefficient (anomalous dispersion coefficient) near the frequency range where the optical frequency comb is desired to be generated. In one embodiment of this disclosure, the height of the microring resonator can be 500-700 nm, and the width can be 1000-4000 nm.

[0028] In addition, the dispersion curve of the resonant cavity can be adjusted by adjusting the refractive index distribution in the waveguide.

[0029] In the embodiments of this disclosure, the pump light, the dispersion curve of the microring resonator, and the third-order nonlinearity jointly determine the time-domain waveform and the shape of the frequency-domain comb spectrum of the optical field. By adjusting the intensity and frequency of the pump light and the dispersion curve of the microring resonator, based on the third-order nonlinear effect of the nonlinear medium, the "optical frequency comb" generated by the on-chip microring resonator 23 is a broadband incoherent optical frequency comb signal.

[0030] Figure 2 This is a real-time graph of a broadband incoherent optical frequency comb signal generated according to embodiments of the present disclosure. Figure 2 a and b are the real-time spectral and time-domain curves of the O-band (1260nm-1360nm) of the broadband incoherent optical frequency comb signal. Figure 2 c and d are the real-time spectral and time-domain curves of the C-band (1530nm-1565nm) of the broadband incoherent optical frequency comb signal. Figure 2 As shown in Figure a, in the O-band, the 3dB bandwidth of the optical frequency comb signal is approximately 25nm, and the signal power is greater than 15mW. Figure 2 As shown in Figure c, in the C-band, the 3dB bandwidth of the optical frequency comb signal is approximately 40nm, and the signal power is greater than 15mW. Figure 2As shown in b and d, in the O-band and C-band, the optical frequency comb is not pulse-distributed in the time domain, but highly disordered with a very short coherence length, making it more suitable for high-precision detection.

[0031] Figure 3 It is an average time integral plot of a broadband incoherent optical frequency comb signal generated according to embodiments of the present disclosure. Figure 3 a and b are the average time integral plots of the O-band (1260nm-1360nm) spectrum and time domain of the broadband incoherent optical frequency comb signal. Figure 3 c and d are the average time-integral plots of the spectrum and time domain of the C-band (1530nm-1565nm) of a broadband incoherent optical frequency comb signal. Figure 2 Similarly, from Figure 3 It can also be seen that the optical frequency comb signal disclosed herein is a broadband, high-power, incoherent optical frequency comb signal.

[0032] By adjusting the dispersion profile of the microring resonator, for example, by designing the dimensions of the on-chip microring resonator, it is possible to achieve a desired negative dispersion coefficient within a desired frequency range. Furthermore, it is possible to achieve a desired negative dispersion coefficient across multiple frequency ranges. In embodiments of this disclosure, for example, the dispersion profile of the microring resonator can be made to have negative dispersion coefficients in both the O-band (1260nm-1360nm) and C-band (1530nm-1565nm) of optical communication. Therefore, by adjusting the pump light frequency to the O-band and C-band respectively, incoherent broadband optical frequency combs in the O-band and C-band can be obtained respectively.

[0033] Therefore, the optical transceiver chip according to the embodiments of this disclosure can be flexibly designed with on-chip micro-ring waveguides according to the band requirements, thereby generating spectra of different bands, which is more conducive to the flexible application of high-precision integrated fiber optic gyroscopes.

[0034] In embodiments of this disclosure, the nonlinear medium of the on-chip microring resonator 23 may include a medium with a high third-order nonlinear effect. Furthermore, to fabricate the on-chip microring resonator 23, the selected material can be fabricated using CMOS-compatible processes. For example, materials for the nonlinear medium include, but are not limited to: silicon nitride (Si3N4), silicon oxide (SiO2), doped silicon glass, silicon, aluminum nitride (AlN), and aluminum gallium arsenide (AlGaAs). Those skilled in the art will also recognize other media compatible with CMOS processes and possessing sufficiently high third-order nonlinear effects, and these media are also included within the scope of this disclosure.

[0035] The pump source 1 in embodiments of this disclosure can be a light source that provides a pump signal with a desired frequency and intensity, including a distributed feedback (DFB) laser or a distributed Bragg mirror (DBR) laser. In some embodiments of this disclosure, the pump source 1 can be separate from the optical transceiver chip 100, and the pump light generated by the pump source 1 can be coupled to the optical transceiver chip 100 via, for example, a light source coupling device 21. The light source coupling device can couple between the pump source 1 and the on-chip microring resonator 23, and couple the pump light from the pump source 1 to the on-chip microring resonator 23. Thus, the pump source 1 can employ various types of light sources, and its design is less restricted, thereby obtaining pump light with more desired characteristics. In other embodiments of this disclosure, the pump source 1 can be integrated into the optical transceiver chip 100 and constitute a part of the optical transceiver chip 100, i.e., the pump source is an on-chip laser. For example, the pump source 1 can be a semiconductor laser formed on the optical transceiver chip 100 by semiconductor heterogeneous integration or hybrid integration processes. This allows for increased device integration and reduced overall device size. The pump source 1 can be an InP laser diode chip.

[0036] In the embodiments of this disclosure, an on-chip laser and an on-chip microring resonator can be combined into a single chip through heterogeneous integration. Heterogeneous integration allows for the fusion of the advantages of different semiconductor materials, processes, structures, and components or chips, enabling more powerful and complex functions, increased flexibility, and other benefits.

[0037] like Figure 1 As shown, the optical transceiver chip 100 for an interferometric fiber optic gyroscope according to an embodiment of this disclosure may further include an optical fiber coupling device 27. This optical fiber coupling device 27 is configured to couple to an on-chip microring resonator 23 and receive incoherent optical frequency comb signals. The optical fiber coupling device 27 is also configured to couple to the sensing fiber 4 of the interferometric fiber optic gyroscope, and to provide the incoherent optical frequency comb signals to the sensing fiber 4 and receive return optical signals from the sensing fiber 4.

[0038] Interferometric fiber optic gyroscopes have a fiber optic loop serving as the sensing fiber and are essentially ring interferometers operating based on the Sagnac effect. The Sagnac effect is a light-related effect propagating in a closed optical path rotating relative to inertial space. Light emitted from the same source splits into two beams of similar characteristics, propagating in opposite directions within the same closed optical path, eventually converging at the original split point. However, if the closed optical path rotates around an axis perpendicular to the plane containing the closed path relative to inertial space, the optical path lengths of the two beams will differ, resulting in an optical path difference, known as the Sagnac phase shift. This optical path difference is proportional to the rotational angular velocity. Therefore, knowing the optical path difference and its corresponding phase difference allows us to determine the rotational angular velocity.

[0039] Using a multi-turn fiber optic path can enhance the Sagnac effect, increase the Sagnac phase shift, and significantly reduce the optical path size of the fiber optic gyroscope. Once the waveguide geometry and operating wavelength are determined, the phase difference depends only on the system's rotational speed; this is the working principle of using a fiber optic gyroscope to detect rotational angular velocity.

[0040] The types of fiber optic gyroscopes utilizing the Sagnac effect include interferometric fiber optic gyroscopes and resonant fiber optic gyroscopes. In the embodiments of this disclosure, an interferometric fiber optic gyroscope is employed. Its working principle utilizes the interference light generated when light propagating in the forward and reverse directions mixes at the detector. This interference light reflects the phase shift caused by the Sagnac effect. The rotational angular velocity of the fiber optic gyroscope can be obtained by appropriately processing the electrical signal detected by the detector.

[0041] like Figure 1 As shown, the sensing fiber 4 is a multi-turn fiber loop, with its two ends coupled to the upper and lower ports of the fiber coupling device 27, respectively. The sensing fiber 4 can be a piezoelectric modulation-enabled polarization-maintaining fiber. The fiber coupling device 27 receives an incoherent broadband optical frequency comb signal from the on-chip micro-ring resonator 23 and splits the optical frequency comb signal into two beams through the Y-shaped waveguide of the fiber coupling device 27. One optical frequency comb signal in the upper arm of the Y-waveguide of the fiber coupling device 27 is coupled into the fiber loop from the upper port and propagates clockwise, then returns to the lower arm of the Y-waveguide from the lower port. The other optical frequency comb signal in the lower arm of the Y-waveguide of the fiber coupling device 27 enters the fiber loop from the lower port and propagates counterclockwise, then returns to the upper arm of the Y-waveguide from the upper port. The two returning beams can interfere, and the intensity change of the interference signal reflects the angular velocity experienced by the sensing fiber 4.

[0042] like Figure 1 As shown, the optical transceiver chip 100 for an interferometric fiber optic gyroscope according to an embodiment of this disclosure may further include a photodetector 31 configured to be coupled to the fiber optic coupler 27, receiving the returned optical signal and detecting an interference optical signal based on the interference between the returned optical signals. Two beams of light returning from the sensing fiber 4 to the fiber optic coupler 27 are provided to the photodetector 31, and interference occurs at the photodetector 31. Thus, the photodetector 31 can detect the interference signal reflecting the angular velocity experienced by the sensing fiber 4. By analyzing this interference signal, the angular velocity experienced by the sensing fiber 4 can be determined.

[0043] The embodiments of this disclosure utilize such incoherent optical frequency comb signals to operate interferometric fiber optic gyroscopes. In interferometric fiber optic gyroscopes, to reduce errors caused by factors such as reverse Rayleigh scattering, it is desirable to provide a broadband incoherent optical frequency comb signal. The broadband incoherent optical frequency comb signal generated by the microring resonator in the embodiments of this disclosure can improve the detection accuracy of the interferometric fiber optic gyroscope and is suitable for application in interferometric fiber optic gyroscopes.

[0044] The fiber optic coupling device 27 may further include a modulation element for open-loop or closed-loop modulation of the incoherent optical frequency comb signal supplied to the sensing fiber, thereby increasing the detection accuracy of the fiber optic gyroscope. Open-loop modulation refers to introducing a phase delay into the input signal of the fiber optic gyroscope to make it operate at the position where the slope of the cosine function is maximum, thus improving the sensitivity of the fiber optic gyroscope. Closed-loop modulation refers to adding a feedback loop to the open-loop fiber optic gyroscope device, introducing a feedback phase shift opposite to the phase shift caused by rotation into the input signal of the fiber optic gyroscope, while maintaining the fiber optic gyroscope operating at the position where the slope of the cosine function is maximum. The angular velocity of the fiber optic gyroscope is then calculated based on the feedback phase shift, greatly increasing the sensitivity of the fiber optic gyroscope.

[0045] The technical solutions for open-loop and closed-loop modulation of fiber optic gyroscopes are known to those skilled in the art and will not be described in detail here.

[0046] This disclosure provides an incoherent optical frequency comb based on an on-chip microring resonator, which can be integrated into a chip and is therefore suitable for the miniaturization and integration of fiber optic gyroscopes. The optical frequency comb signal generated by this incoherent optical frequency comb has a wider spectral range, lower light source coherence length, and higher power than traditional SLD and ASE spectra. Therefore, embodiments of this disclosure can provide a wide-spectral-range, high-power, incoherent optical frequency comb signal, meeting the requirements of interferometric fiber optic gyroscopes and further improving the measurement accuracy of fiber optic gyroscopes.

[0047] like Figure 1 As shown, the optical transceiver chip 100 for an interferometric fiber optic gyroscope in an embodiment of this disclosure may further include a phase modulation device 22 coupled between the pump light source 1 and the on-chip microring resonator 23. It is configured to receive the pump light signal backscattered from the on-chip microring resonator 23, adjust the phase of the backscattered pump light signal, and provide the phase-modulated pump light signal to the pump light source 1, thereby generating a self-injected phase lock between the pump light source 1 and the on-chip microring resonator 23.

[0048] In embodiments of this disclosure, the phase of the pump light signal backscattered from the on-chip microring resonator 23 can be adjusted by, for example, controlling the operating current of the phase modulation device 22, such that the difference between the phase of the pump signal light from the pump light source 1 and the phase of the pump light signal backscattered from the on-chip microring resonator 23 is within a predetermined range, and self-injection locking is achieved when the pump light frequency matches the resonant frequency of the microring resonator.

[0049] Self-injection locking between the pump source and the microring resonator can stabilize the pump light and bring its frequency closer to the resonant frequency of the microring resonator by utilizing optical feedback from the microcavity resonator in a desired phase relationship. Therefore, by employing self-injection locking, frequency noise can be reduced and it can facilitate the generation of an optical frequency comb.

[0050] In embodiments of this disclosure, the frequency of the pump optical signal can be adjusted to match the resonant peak of the on-chip microring resonator. For example, in embodiments of this disclosure, a frequency-tunable laser can be used as the pump source 1. Various methods for adjusting the frequency of the pump optical signal will be apparent to those skilled in the art, and all of these are included within the scope of this application.

[0051] The on-chip microring resonator 23 may further include a microring modulation device 28 for controlling the position of the resonant peak of the on-chip microring resonator. In embodiments of this disclosure, the microring modulation device 28 may be a heating element, a piezoelectric element, or a semiconductor PIN junction, etc. In one embodiment of this disclosure, the microring modulation device 28 may be a heating electrode overlapping with the microring resonant cavity. By controlling the position of the resonant peak of the on-chip microring resonator with the microring modulation device 28, a desired broadband incoherent optical frequency comb signal can be generated. The methods for forming the microring modulation device 28 are known to those skilled in the art and will not be described in detail here.

[0052] like Figure 1 As shown, the optical transceiver chip 100 for an interferometric fiber optic gyroscope according to an embodiment of this disclosure may further include a power distribution device 25 and a power meter 32. The power distribution device 25 is configured to be coupled to an on-chip microring resonator 23 and to receive an incoherent broadband optical frequency comb signal. The power distribution device 25 is also configured to distribute the incoherent optical frequency comb signal to an optical fiber coupling device 27 and the power meter 32. The power meter 32 is configured to be coupled to the power distribution device 25 and to measure the power of the incoherent broadband optical frequency comb signal.

[0053] The power distribution device 25 can, for example, distribute the incoherent broadband optical frequency comb signal received from the on-chip microring resonator 23 to the power meter 32 and the fiber optic coupler 27 according to a predetermined ratio. This predetermined ratio can be, for example, 1:9, 2:8, 3:7, 4:6, or 5:5. The power meter 32 measures the power of the received optical signal and calculates the power of the incoherent broadband optical frequency comb signal generated by the on-chip microring resonator 23 based on the predetermined power distribution ratio allocated by the power distribution device 25.

[0054] Therefore, in the embodiments of this disclosure, the power of the incoherent broadband optical frequency comb signal can be determined, and the operating state of the optical transceiver chip 100 can be detected.

[0055] In addition, the power distribution device 25 can also provide the return optical signal from the sensing optical fiber 4 received from the optical fiber coupling device 27 to the photoelectric detection device 31.

[0056] In addition, such as Figure 1 As shown, the optical transceiver chip 100 for an interferometric fiber optic gyroscope according to an embodiment of this disclosure may further include a power distribution device 24 coupled between the on-chip microring resonator 23 and the power distribution device 25, for providing the return optical signal received from the sensing fiber 4 from the power distribution device 25 to the photodetector 31. In an embodiment of this disclosure, the power distribution device 24 distributes the return optical signal from the sensing fiber 4 to the photodetector 31 and the on-chip microring resonator 23 according to a predetermined ratio.

[0057] like Figure 1 As shown, the optical transceiver chip 100 for an interferometric fiber optic gyroscope in an embodiment of this disclosure may further include a polarization control device 26, configured to be coupled between the on-chip microring resonator 23 and the fiber optic coupling device 27 and to control the polarization of the measured incoherent broadband optical frequency comb signal.

[0058] Interferometric fiber optic gyroscopes typically require the optical signal entering the sensing fiber to be a polarized signal. The incoherent broadband optical frequency comb signal from the on-chip microring resonator in the embodiments of this disclosure already possesses a strong degree of polarization, which meets the requirements of an interferometric fiber optic gyroscope. Furthermore, to further enhance the polarization of the optical signal, a polarization control device 26 can be added between the on-chip microring resonator 23 and the fiber optic coupling device 27.

[0059] Figure 1 The on-chip microring resonator 23 shown includes a straight waveguide and a microring resonator cavity, but those skilled in the art will understand that the on-chip microring resonator 23 may include other structures. For example, the on-chip microring resonator 23 may be an on-chip / off-chip microring resonator, that is, it includes two straight waveguides, one above the other and a single microring resonator cavity located between and coupled to the two straight waveguides.

[0060] For example, the multiple functions included in one unit in the above embodiments can be implemented by separate devices. Alternatively, the multiple functions implemented by multiple units in the above embodiments can be implemented by separate devices respectively. In addition, one of the above functions can be implemented by multiple units. Such configurations are included within the scope of this disclosure.

[0061] The terms "comprising," "including," or any other variations thereof used in embodiments of this disclosure are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0062] The term "or" in this disclosure means inclusive "or," not exclusive "or." A reference to a "first" component does not necessarily require the provision of a "second" component. Furthermore, unless explicitly indicated, "first" or "second" component does not imply a restriction on the order in which the components are mentioned. The term "based on" means "at least partially based on."

Claims

1. An optical transceiver chip for an interferometric fiber optic gyroscope, comprising: An on-chip microring resonator includes a nonlinear medium and is configured to couple to and receive a pump light signal from the pump light source, and generates an incoherent broadband optical comb signal from the pump light signal based on the third-order nonlinear effect of the nonlinear medium. An optical fiber coupling device is configured to couple to an on-chip microring resonator and receive an incoherent broadband optical frequency comb signal. The optical fiber coupling device is also configured to couple to the sensing fiber of an interferometric fiber optic gyroscope and provide the incoherent broadband optical frequency comb signal to the sensing fiber of the interferometric fiber optic gyroscope and receive the return optical signal from the sensing fiber. and The photoelectric detection device is configured to be coupled to an optical fiber coupler, receive the returned optical signal, and detect the interference optical signal based on the interference between the returned optical signals.

2. The optical transceiver chip according to claim 1 further includes a phase modulation device coupled between the pump light source and the on-chip microring resonator, configured to receive a pump light signal backscattered from the on-chip microring resonator, adjust the phase of the backscattered pump light signal, and provide the phase-modulated pump light signal to the pump light source, thereby generating a self-injected phase lock between the pump light source and the on-chip microring resonator.

3. The optical transceiver chip according to claim 1, wherein, The frequency of the pump optical signal can be adjusted to match the resonant peak of the on-chip microring resonator.

4. The optical transceiver chip according to claim 1, wherein, The on-chip microring resonator also has a microring modulation device for controlling the position of the resonant peak of the on-chip microring resonator.

5. The optical transceiver chip according to claim 4, wherein, The micro-ring modulation device includes a heating element, a piezoelectric element, and a semiconductor PIN junction.

6. The optical transceiver chip according to claim 1 further includes a power distribution device and a power meter, wherein the power distribution device is configured to be coupled to an on-chip microring resonator and receive an incoherent broadband optical frequency comb signal, and the power distribution device is further configured to distribute the incoherent optical frequency comb signal to an optical fiber coupling device and a power meter, wherein the power meter is configured to be coupled to the power distribution device and measure the power of the incoherent broadband optical frequency comb signal.

7. The optical transceiver chip according to claim 1 further includes a polarization control device configured to be coupled between the on-chip microring resonator and the optical fiber coupling device and to control the polarization of the incoherent broadband optical frequency comb signal.

8. The optical transceiver chip according to claim 1, wherein, An on-chip microring resonator consists of a straight waveguide and a microring resonant cavity that are coupled together.

9. The optical transceiver chip according to claim 1 further includes an on-chip laser as a pump light source.

10. The optical transceiver chip according to claim 1, wherein, On-chip lasers and on-chip microring resonators are combined into a single chip through semiconductor heterogeneous integration.

11. The optical transceiver chip according to claim 1, wherein, Third-order nonlinear effects include at least one of the following: self-phase modulation effect, cross-phase modulation effect, four-wave mixing effect, and modulation instability effect.

12. The optical transceiver chip according to claim 1 further includes a light source coupling device configured to couple between the pump light source and the on-chip microring resonator, and to couple the pump light from the pump light source to the on-chip microring resonator.

13. An interferometric fiber optic gyroscope, comprising: The optical transceiver chip according to any one of claims 1-12; as well as Induction fiber optics.

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