A fully integrated multi-axis optical gyroscope on a chip, a preparation method and a working method

Abstract

The present invention discloses an on-chip fully integrated multi-axis optical gyroscope, a preparation method and a working method, which belong to the field of optoelectronic integration, and include active devices and passive devices, wherein the passive devices include a light transmission waveguide, a polarizer, a beam splitter and a double-layer waveguide ring composed of SiN waveguides, and the active devices include a wide-spectrum light source, a phase modulator and a photodetector heterogeneously integrated by SiN waveguides, and the wide-spectrum light source, the light transmission waveguide, the polarizer, the beam splitter, the phase modulator, the double-layer waveguide ring and the photodetector are arranged in sequence along the direction of light propagation. The present invention adopts the above-mentioned on-chip fully integrated multi-axis optical gyroscope, the preparation method and the working method, and based on the relevant technology of micro-nano optical chips, realizes the complete monolithic integration of all core components of the optical gyroscope, thereby further reducing the size without affecting the accuracy.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic integration, and in particular to an on-chip fully integrated multi-axis optical gyroscope, a preparation method and a working method. Background Art

[0002] Fiber optic gyroscope is a fiber optic angular velocity sensor. Like the ring laser gyroscope, it has the advantages of no mechanical moving parts, no warm-up time, insensitivity to acceleration, wide dynamic range, digital output, and small size. In addition, the fiber optic gyroscope overcomes the fatal shortcomings of the ring laser gyroscope, such as high cost and locking phenomenon, and thus has a wide range of application prospects.

[0003] Traditional fiber optic gyroscopes, especially interferometric fiber optic gyroscopes using the Sagnac effect, are widely used in key fields such as defense, aerospace, etc. around the world due to their excellent stability, low power consumption, and accuracy that can meet wide-area navigation requirements (spanning from 0.1° / hour to 0.001° / hour).

[0004] At the same time, with the rapid development of drones and unmanned driving technology, the fiber optic gyroscope, as a core component of the navigation system, faces the following challenges: how to further reduce the size and weight while ensuring the original high-precision advantages to adapt to the requirements of compact design of unmanned systems has become the key to the current upgrade. Summary of the invention

[0005] To solve the above problems, the present invention provides an on-chip fully integrated multi-axis optical gyroscope, a preparation method and a working method. Based on the relevant technology of micro-nano optical chips, the complete monolithic integration of all core components of the optical gyroscope is achieved, thereby further reducing the size without affecting the accuracy.

[0006] To achieve the above-mentioned purpose, the present invention provides an on-chip fully integrated multi-axis optical gyroscope, comprising active devices and passive devices, wherein the passive devices include a light transmission waveguide, a polarizer, a beam splitter and a double-layer waveguide ring formed by a SiN waveguide, and the active devices include a broadband light source, a phase modulator and a photodetector heterogeneously integrated by the SiN waveguide, wherein the broadband light source, the light transmission waveguide, the polarizer, the beam splitter, the phase modulator, the double-layer waveguide ring and the photodetector are connected on-chip via the SiN waveguide, and the broadband light source, the light transmission waveguide, the polarizer, the beam splitter, the phase modulator, the double-layer waveguide ring and the photodetector are arranged in sequence along the direction of light propagation.

[0007] Preferably, the cross-sectional dimensions of the light transmission waveguide, the polarizer, the beam splitter and the SiN waveguide of the double-layer waveguide ring are the same, and the ratio of the waveguide width to the waveguide thickness of the light transmission waveguide, the polarizer, the beam splitter and the SiN waveguide of the double-layer waveguide ring is not greater than 1:50;

[0008] The polarizer is formed by cascading multiple sections of 90° SiN curved waveguides, and the bending radius of each section of the SiN curved waveguide is 100μm-120μm;

[0009] The beam splitter is an MMI structure;

[0010] The double-layer waveguide ring is a two-layer waveguide ring structure. Each layer of the waveguide ring structure is based on an Archimedean spiral structure, and the number of rings of each layer of the waveguide ring structure is a multiple of 4. The input port and the output port of the double-layer waveguide ring are arranged on the same layer. The input port and the output port of the double-layer waveguide ring, as well as the two layers of the waveguide rings, are coupled and connected via SiN tapered waveguides.

[0011] Preferably, the polarization extinction ratio of the polarizer is not less than 60 dB;

[0012] The ring transmission loss of the double-layer waveguide is ≤1dB / m, and the bending radius is ≥500μm.

[0013] Preferably, the broadband light source is heterogeneously integrated with a III-V group material and a SiN waveguide, and the III-V group material is one of InP and InGaAs and a combination thereof;

[0014] The phase modulator is heterogeneously integrated with thin-film lithium niobate and SiN waveguide, and the modulation area of ​​the phase modulator is a thin-film lithium niobate waveguide structure;

[0015] The die of the photodetector is heterogeneously integrated with a Group IV material and a SiN waveguide, where the Group IV material is Si or Ge.

[0016] Preferably, the broad spectrum light source is an edge emission structure, with a spectrum width of 40nm-50nm and an output power of 6mW-8mW;

[0017] The modulation efficiency of the phase modulator is ≥1V·cm;

[0018] The responsivity of the photodetector is 0.9A / W-1A / W, the dark current is less than 10nA under -3V bias, and the bandwidth is 5GHz.

[0019] The method for preparing an on-chip fully integrated multi-axis optical gyroscope comprises the following steps:

[0020] The broadband light source, light transmission waveguide, polarizer, beam splitter, phase modulator, double-layer waveguide ring and photodetector are integrated on the chip respectively;

[0021] The process of integrating the broadband light source is as follows: first, grow the III-V group material on the Si substrate, then perform structural etching according to the circuit pattern, then dope the III-V group material, and finally grow electrodes on the surface of the III-V group material;

[0022] The process of the phase modulator is as follows: first, a thin-film lithium niobate wafer is bonded to a SiN wafer, then a straight lithium niobate waveguide is patterned in the modulation area according to the circuit pattern, and then electrodes are added to the lithium niobate cladding;

[0023] The process of the photodetector is: growing a Group IV material on a Si substrate as a light absorption layer, then doping the Si substrate and the top layer of the Group IV material respectively, and finally growing electrodes on the Si substrate and the Group IV material.

[0024] Preferably, in the process of integrating the wide-spectrum light source, a first layer of InP, a first layer of InGaAs, a second layer of InP, and a second layer of InGaAs are sequentially grown on the Si substrate, and an N-type semiconductor is doped in the first layer of InP, a P-type semiconductor is doped on both sides of the second layer of InP, and a P-type semiconductor is doped on the second layer of InGaAs;

[0025] In the phase modulator process, electrodes are located on both sides of the lithium niobate cladding, and the electrodes are arranged in a push-pull configuration;

[0026] In the process of photodetectors, the Group IV material is Ge.

[0027] The working method of the on-chip fully integrated multi-axis optical gyroscope comprises the following steps:

[0028] In the wide-spectrum light source, the generated light first enters the Si tapered waveguide through the first layer of InP tapered waveguide, and then enters the light transmission waveguide composed of the SiN tapered waveguide through the Si tapered waveguide coupling for transmission, and then is polarized by the polarizer and converted into a high polarization state. After passing through the beam splitter, it enters the phase modulator through interlayer coupling. In the phase modulator, the unmodulated light enters the lithium niobate straight waveguide through the interlayer coupling between the SiN waveguide and the lithium niobate straight waveguide. The modulated light enters the SiN waveguide from the lithium niobate straight waveguide, and then enters the double-layer waveguide ring in two ways. After completing the transmission in the ring, optical interference is realized at the phase modulator, and finally enters the photodetector. In the photodetector, the light enters the light absorption layer through the SiN waveguide and Si waveguide evanescent wave coupling, and the electrical signal generated after the photoelectric conversion is output through the gold wire bonding leads.

[0029] The present invention has the following beneficial effects:

[0030] 1. All components of a multi-axis optical gyroscope (the multi-axis refers to n axes, n ≥ 3) are fully integrated on a single chip through micro-nano processing, replacing the traditional discrete optical gyroscope. The required optical loop is formed through optical fiber connection. Only a single chip and the corresponding detection circuit can achieve the measurement of multi-dimensional sensitive angular velocity in space, which greatly saves the energy of coupling, packaging and debugging, and is a crucial step for the development of gyroscope technology.

[0031] 2. The bonding method between wafers of materials such as III-V materials (InP, InGaAs), IV materials (Si, Ge), and ferroelectric materials (LiNbO3) and SiN wafers is expected to achieve large-scale production.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic structural diagram of an on-chip fully integrated multi-axis optical gyroscope of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of a wide-spectrum light source of an on-chip fully integrated multi-axis optical gyroscope of the present invention;

[0035] Figure 3 A cross-sectional view of a waveguide at a coupling point of a wide-spectrum light source of an on-chip fully integrated multi-axis optical gyroscope of the present invention;

[0036] Figure 4 It is a schematic diagram of the structure of a photoelectric detector of an on-chip fully integrated multi-axis optical gyroscope of the present invention;

[0037] Figure 5 A cross-sectional view of a waveguide at a coupling location of a photodetector of an on-chip fully integrated multi-axis optical gyroscope of the present invention;

[0038] Figure 6 It is a schematic structural diagram of a phase modulator of an on-chip fully integrated multi-axis optical gyroscope of the present invention;

[0039] Figure 7 A cross-sectional view of a waveguide at a coupling portion of a phase modulator of an on-chip fully integrated multi-axis optical gyroscope of the present invention;

[0040] Figure 8 The figure is a schematic diagram of the double-layer waveguide ring structure of an on-chip fully integrated multi-axis optical gyroscope of the present invention.

[0041] Reference numerals

[0042] 1. Broad-spectrum light source; 2. Light transmission waveguide; 3. Polarizer; 4. Beam splitter; 5. Photodetector; 6. Phase modulator; 7. Double-layer waveguide ring. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0044] It should be noted that the terms "include", "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or devices.

[0045] Like reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0047] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] With the continuous development and improvement of micro-nano processing technology, as well as the need for high-efficiency, low-loss optical transmission in the entire field of photonic integrated chips, SiN materials that can meet the needs of optical waveguides can be prepared. And because optical gyroscopes also have certain requirements for device losses, using SiN materials to prepare passive structures that meet the requirements and applying them to optical gyroscope systems is a feasible path to achieve gyroscope miniaturization.

[0049] As the core components of the fiber optic gyroscope, the beam splitter and the overall light transmission structure can be replaced by an on-chip SiN waveguide structure; the phase modulator can be realized through heterogeneous integration or bonding with other materials based on the material compatibility characteristics of SiN; the broadband light source and photodetector can be integrated with the SiN-based chip through the optical method of die bonding; and the sensitive ring structure is connected through polarization-maintaining optical fiber to form an overall integrated optical gyroscope system, which greatly reduces the size and energy consumption of the gyroscope while maintaining the same accuracy, thereby achieving a morphological upgrade of the optical gyroscope.

[0050] Based on the above analysis, the present invention is designed as follows: Figure 1-Figure 8 As shown, an on-chip fully integrated multi-axis optical gyroscope includes active devices and passive devices, the passive devices include a light transmission waveguide 2, a polarizer 3, a beam splitter 4 and a double-layer waveguide ring 7 composed of SiN waveguides, and the active devices include a broadband light source 1, a phase modulator 6, and a photodetector 5 heterogeneously integrated by SiN waveguides, the broadband light source 1, the light transmission waveguide 2, the polarizer 3, the beam splitter 4, the phase modulator 6, the double-layer waveguide ring 7 and the photodetector 5 are connected on-chip via the SiN waveguide, and the broadband light source 1, the light transmission waveguide 2, the polarizer 3, the beam splitter 4, the phase modulator 6, the double-layer waveguide ring 7 and the photodetector 5 are arranged in sequence along the direction of light propagation.

[0051] Specifically, the cross-sectional dimensions of the SiN waveguides of the light transmission waveguide 2, the polarizer 3, the beam splitter 4, and the double-layer waveguide ring 7 are the same, which improves the stability of the optical performance of the chip and reduces the difficulty of processing. In addition, the ratio of the waveguide width to the waveguide thickness of the SiN waveguides of the light transmission waveguide 2, the polarizer 3, the beam splitter 4, and the double-layer waveguide ring 7 is not greater than 1:50, so that the three bands (850nm / 1310nm / 1550nm) used in the optical gyroscope can meet the design requirements of the system; wherein, the polarizer 3 is formed by cascading multiple sections of 90° SiN curved waveguides, and the bending radius of each section of the SiN curved waveguide is 1 00μm-120μm; beam splitter 4 is an MMI structure to accurately control the size of the output optical power of each port, that is, the beam splitting ratio is 1:1, 1:1:1; double-layer waveguide ring 7 is a two-layer waveguide ring structure, each layer of the waveguide ring structure is based on the Archimedean spiral structure, and the number of rings of each layer of the waveguide ring structure is a multiple of 4, so as to simulate the four-level symmetric structure of the optical fiber and reduce the influence of the temperature effect on the accuracy of the gyro system. The input port and output port of the double-layer waveguide ring 7 are arranged on the same layer, and the input port and output port of the double-layer waveguide ring 7, as well as the two layers of waveguide rings, are coupled and connected by SiN tapered waveguides. And the polarization extinction ratio of polarizer 3 is not less than 60dB, achieving a higher extinction ratio, ensuring that the light emitted by the light source enters the subsequent device with a higher degree of polarization; the ring transmission loss of the double-layer waveguide is ≤1dB / m, and the bending radius is ≥500μm.

[0052] The broadband light source 1 is heterogeneously integrated with a III-V group material and a SiN waveguide, and the III-V group material is one of InP, InGaAs and a combination thereof; the phase modulator 6 is heterogeneously integrated with a thin film lithium niobate and a SiN waveguide, and the modulation region of the phase modulator 6 is a thin film lithium niobate waveguide structure; the die of the photodetector 5 is heterogeneously integrated with a IV group material and a SiN waveguide, and the IV group material is Si or Ge.

[0053] The wide-spectrum light source 1 is an edge-emitting structure with a spectrum width of 40nm-50nm and an output power of 6mW-8mW; the modulation efficiency of the phase modulator 6 is ≥1V·cm; the responsivity of the photodetector 5 is 0.9A / W-1A / W, the dark current is <10nA under a bias of -3V, and the bandwidth is 5GHz.

[0054] The method for preparing an on-chip fully integrated multi-axis optical gyroscope comprises the following steps:

[0055] A broadband light source 1, a light transmission waveguide 2, a polarizer 3, a beam splitter 4, a phase modulator 6, a double-layer waveguide ring 7 and a photodetector 5 are integrated on the chip respectively;

[0056] The process of integrating the broadband light source 1 is as follows: first, a III-V group material is grown on a Si substrate, then a structure is etched according to a circuit pattern, then the III-V group material is doped, and finally an electrode is grown on the surface of the III-V group material;

[0057] The process of phase modulator 6 is as follows: firstly, a thin film lithium niobate wafer is bonded on a SiN wafer, then a lithium niobate straight waveguide is patterned in the modulation area according to the circuit pattern, and then electrodes are added on the lithium niobate cladding;

[0058] The process of the photodetector 5 is as follows: growing a Group IV material on a Si substrate as a light absorption layer, then doping the Si substrate and the top layer of the Group IV material respectively, and finally growing electrodes on the Si substrate and the Group IV material to form a vertical PIN structure photodetector 5.

[0059] In the process of integrating the wide-spectrum light source 1, a first layer of InP, a first layer of InGaAs, a second layer of InP, and a second layer of InGaAs are sequentially grown on the Si substrate, and an N-type semiconductor is doped in the first layer of InP, a P-type semiconductor is doped on both sides of the second layer of InP, and a P-type semiconductor is doped on the second layer of InGaAs;

[0060] In the process of phase modulator 6, the electrodes are located on both sides of the lithium niobate cladding, and the electrodes are arranged in a push-pull structure;

[0061] In the process of photodetector 5, the Group IV material is Ge.

[0062] The working method of the on-chip fully integrated multi-axis optical gyroscope comprises the following steps:

[0063] In the wide-spectrum light source 1, the generated light first enters the Si tapered waveguide through the first layer of InP tapered waveguide, and then enters the light transmission waveguide 2 composed of the SiN tapered waveguide through the Si tapered waveguide coupling for transmission, and then passes through the polarizer 3 for polarization, and is converted into a high polarization state. After passing through the beam splitter 4, the interlayer coupling enters the phase modulator 6. In the phase modulator 6, the unmodulated light enters the lithium niobate straight waveguide through the interlayer coupling between the SiN waveguide and the lithium niobate straight waveguide. The modulated light enters the SiN waveguide from the lithium niobate straight waveguide, and then enters the double-layer waveguide ring 7 in two ways. After completing the transmission in the ring, optical interference is realized at the phase modulator 6, and finally enters the photodetector 5. In the photodetector 5, the light enters the light absorption layer through the SiN waveguide and the Si waveguide evanescent wave coupling. The electrical signal generated after the photoelectric conversion is output through the gold wire bonding lead, and enters the subsequent multi-axis gyroscope processing circuit to realize the detection of the rotation angular velocity of the full spatial dimension.

[0064] Therefore, the present invention adopts the above-mentioned on-chip fully integrated multi-axis optical gyroscope, preparation method and working method, based on the relevant technology of micro-nano optical chip, to achieve complete monolithic integration of all core components of the optical gyroscope, thereby further reducing the size without affecting the accuracy.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. An on-chip fully integrated multi-axis optical gyroscope, comprising active components and passive components, characterized in that: The passive devices include a light transmission waveguide, a polarizer, a beam splitter, and a double-layer waveguide ring formed by a SiN waveguide, and the active devices include a broadband light source, a phase modulator, and a photodetector heterogeneously integrated by the SiN waveguide. The broadband light source, the light transmission waveguide, the polarizer, the beam splitter, the phase modulator, the double-layer waveguide ring, and the photodetector are connected on-chip via the SiN waveguide, and the broadband light source, the light transmission waveguide, the polarizer, the beam splitter, the phase modulator, the double-layer waveguide ring, and the photodetector are arranged in sequence along the direction of light propagation. The cross-sectional dimensions of the SiN waveguide of the light transmission waveguide, polarizer, beam splitter and double-layer waveguide ring are the same, and the ratio of the waveguide width to the waveguide thickness of the SiN waveguide of the light transmission waveguide, polarizer, beam splitter and double-layer waveguide ring is not greater than 1:50; The polarizer is formed by cascading multiple sections of 90° SiN curved waveguides, and the bending radius of each section of the SiN curved waveguide is 100μm-120μm; The beam splitter is an MMI structure; The double-layer waveguide ring is a two-layer waveguide ring structure. Each layer of the waveguide ring structure is based on an Archimedean spiral structure, and the number of rings of each layer of the waveguide ring structure is a multiple of 4. The input port and the output port of the double-layer waveguide ring are arranged on the same layer. The input port and the output port of the double-layer waveguide ring, as well as the two layers of the waveguide rings, are coupled and connected via SiN tapered waveguides.

2. The on-chip fully integrated multi-axis optical gyroscope according to claim 1, characterized in that: The polarization extinction ratio of the polarizer is not less than 60dB; The ring transmission loss of the double-layer waveguide is ≤1dB / m, and the bending radius is ≥500μm.

3. The on-chip fully integrated multi-axis optical gyroscope according to claim 1, characterized in that: The broadband light source is heterogeneously integrated with a III-V group material and a SiN waveguide, wherein the III-V group material is one of InP and InGaAs or a combination thereof; The phase modulator is heterogeneously integrated with thin-film lithium niobate and SiN waveguide, and the modulation area of ​​the phase modulator is a thin-film lithium niobate waveguide structure; The die of the photodetector is heterogeneously integrated with a Group IV material and a SiN waveguide, where the Group IV material is Si or Ge.

4. The on-chip fully integrated multi-axis optical gyroscope according to claim 3, characterized in that: The broadband light source is an edge-emitting structure with a spectrum width of 40nm-50nm and an output power of 6mW-8mW; The modulation efficiency of the phase modulator is ≥1V·cm; The responsivity of the photodetector is 0.9A / W-1A / W, the dark current is less than 10nA under -3V bias, and the bandwidth is 5GHz.

5. A method for preparing an on-chip fully integrated multi-axis optical gyroscope as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: The broadband light source, light transmission waveguide, polarizer, beam splitter, phase modulator, double-layer waveguide ring and photodetector are integrated on the chip respectively; The process of integrating the broadband light source is as follows: first, grow the III-V group material on the Si substrate, then perform structural etching according to the circuit pattern, then dope the III-V group material, and finally grow electrodes on the surface of the III-V group material; The process of the phase modulator is as follows: first, a thin-film lithium niobate wafer is bonded to a SiN wafer, then a straight lithium niobate waveguide is patterned in the modulation area according to the circuit pattern, and then electrodes are added to the lithium niobate cladding; The process of the photodetector is: growing a Group IV material on a Si substrate as a light absorption layer, then doping the Si substrate and the top layer of the Group IV material respectively, and finally growing electrodes on the Si substrate and the Group IV material.

6. The method for preparing an on-chip fully integrated multi-axis optical gyroscope according to claim 5, characterized in that: In the process of integrating the wide-spectrum light source, a first layer of InP, a first layer of InGaAs, a second layer of InP, and a second layer of InGaAs are sequentially grown on a Si substrate, and an N-type semiconductor is doped in the first layer of InP, a P-type semiconductor is doped on both sides of the second layer of InP, and a P-type semiconductor is doped on the second layer of InGaAs; In the phase modulator process, electrodes are located on both sides of the lithium niobate cladding, and the electrodes are arranged in a push-pull configuration; In the process of photodetectors, the Group IV material is Ge.

7. A method for operating an on-chip fully integrated multi-axis optical gyroscope as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: In the wide-spectrum light source, the generated light first enters the Si tapered waveguide through the first layer of InP tapered waveguide, and then enters the light transmission waveguide composed of the SiN tapered waveguide through the Si tapered waveguide coupling for transmission, and then is polarized by the polarizer and converted into a high polarization state. After passing through the beam splitter, it enters the phase modulator through interlayer coupling. In the phase modulator, the unmodulated light enters the lithium niobate straight waveguide through the interlayer coupling between the SiN waveguide and the lithium niobate straight waveguide. The modulated light enters the SiN waveguide from the lithium niobate straight waveguide, and then enters the double-layer waveguide ring in two ways. After completing the transmission in the ring, optical interference is realized at the phase modulator, and finally enters the photodetector. In the photodetector, the light enters the light absorption layer through the SiN waveguide and Si waveguide evanescent wave coupling, and the electrical signal generated after the photoelectric conversion is output through the gold wire bonding leads.

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