Integrated optical chip, preparation method and optical gyroscope

Abstract

The invention discloses an integrated optical chip, a preparation method and an optical gyroscope, the integrated optical chip comprises a first device layer and a second device layer, the first device layer is provided with a phase modulator, the phase modulator comprises a fourth waveguide used for connecting an interference ring, and the second device layer is provided with a detection unit. The detection unit comprises a first coupler and a detector, the first coupler comprises a first waveguide, a second waveguide and a third waveguide, the first waveguide is used for connecting a light source, the first waveguide is connected with the third waveguide, the second waveguide is connected with the third waveguide, and the third waveguide is connected with the phase modulator; the detector is connected with the second waveguide; wherein the second device layer comprises a first sub-device layer and a second sub-device layer, the coupling loss of the first sub-device layer is larger than that of the second sub-device layer, at least part of the detector is located on the first sub-device layer, and the first coupler is located on the second sub-device layer.

Description

Technical Field

[0001] The present application belongs to the technical field of optical sensors, and in particular, relates to an integrated optical chip, a preparation method and an optical gyroscope. Background Art

[0002] An optical gyroscope is an optical sensor that detects the angular velocity of a moving carrier and is widely used in aerospace, automation control and other fields. As the core component of an optical gyroscope, an optical integrated chip integrates some active and passive components on a single chip, which makes the system lighter and smaller than traditional discrete components.

[0003] However, integrated optical chips still have problems such as low integration and high internal losses that need to be improved. Summary of the invention

[0004] The embodiments of the present application provide an integrated optical chip, a preparation method and an optical gyroscope. The integrated optical chip integrates a coupler, a detector and a phase modulator, which contributes to the miniaturization and lightweight of the optical gyroscope product.

[0005] In a first aspect, an embodiment of the present application provides an integrated optical chip, comprising a first device layer and a second device layer, wherein the first device layer is provided with a phase modulator, the phase modulator comprises a fourth waveguide for connecting an interference ring, the second device layer is provided with a detection unit, the detection unit comprises a first coupler and a detector, the first coupler comprises a first waveguide, a second waveguide and a third waveguide, the first waveguide is used to connect a light source, the first waveguide is connected to the third waveguide, the second waveguide is connected to the third waveguide, and the third waveguide is connected to the phase modulator; the detector is connected to the second waveguide; wherein the second device layer comprises a first sub-device layer and a second sub-device layer, the coupling loss of the first sub-device layer is greater than that of the second sub-device layer, at least part of the detector is located in the first sub-device layer, the first coupler is located in the second sub-device layer, the light beam is transmitted to the phase modulator through the first waveguide and the third waveguide, and is transmitted to the interference ring through the phase modulator, and the test light beam transmitted back by the interference ring is transmitted to the detector through the third waveguide and the second waveguide.

[0006] In some of the embodiments, the integrated optical chip also includes a waveguide cladding, the first sub-device layer is located between the waveguide cladding and the second sub-device layer, the material of the first sub-device layer includes at least one of silicon, gallium arsenide, and indium phosphide, and the material of the second sub-device layer includes silicon nitride.

[0007] In some embodiments, the detector includes an active structure and a photoelectric conversion structure, the active structure is located in the first sub-device layer, the active structure includes a PN junction or a PIN junction, and the photoelectric conversion structure includes at least one of germanium, gold, silver, aluminum, and molybdenum.

[0008] In some of the embodiments, the waveguide cladding is disposed between the first device layer and the second device layer along the thickness direction, or the second device layer is disposed between the first device layer and the waveguide cladding along the thickness direction, and a substrate is provided on a side of the waveguide cladding facing away from the second device layer.

[0009] In some of the embodiments, the integrated optical chip further includes a second coupler disposed in the second sub-device layer, the detection units are provided with N pieces, the N first waveguides are connected to the second couplers, and the second coupler further includes an input waveguide, and the input waveguide is used to connect to a light source.

[0010] In some of the embodiments, the integrated optical chip further includes a polarization beam splitter disposed in the second sub-device layer, the polarization beam splitter is used to obtain TE polarized light, and the polarization beam splitter is connected to the first coupler or the second coupler.

[0011] In some of the embodiments, the integrated optical chip further comprises a light guide groove, wherein the light guide groove is connected to the TM output end of the polarization beam splitter, wherein a light absorbing element is provided in the light guide groove, or the output end of the light guide groove is an obliquely polished end face.

[0012] In a second aspect, an embodiment of the present application provides an optical gyroscope, comprising a light source, an interference ring, and an integrated optical chip provided by any of the aforementioned embodiments, wherein the light source is connected to the first waveguide, and the interference ring is connected to the phase modulator.

[0013] In a third aspect, an embodiment of the present application provides a method for preparing an integrated optical chip, comprising:

[0014] providing a substrate, and forming a waveguide cladding over the substrate;

[0015] forming a patterned first dielectric layer above the waveguide cladding, the first dielectric layer including an active structure of the detector;

[0016] forming a patterned second dielectric layer above the first dielectric layer, wherein the second dielectric layer comprises a first coupler, a first waveguide, a second waveguide, and a third waveguide;

[0017] A first device layer is prepared to form a phase modulator, and the phase modulator is connected to the third waveguide.

[0018] In some embodiments, the integrated optical chip preparation method further comprises:

[0019] forming a first protective layer on the second dielectric layer;

[0020] A first shielding portion is arranged above the protective layer, and the first protective layer and the second dielectric layer are etched to expose the active structure of the detector;

[0021] forming a photoelectric conversion structure above the active structure, wherein the thickness of the photoelectric conversion structure is greater than the thickness of the second dielectric layer;

[0022] A second protective layer is formed above the photoelectric conversion structure, a second shielding portion is arranged above the second protective layer, the second protective layer is etched to obtain a contact hole, a detector electrode is formed in the contact hole, and the detector electrode is electrically connected to at least part of the photoelectric conversion structure.

[0023] The integrated optical chip of the embodiment of the present application is integrated with a detection unit and a phase modulator, so that the integrated optical chip can be assembled with a light source and an interference ring to form an optical gyroscope product, which improves the integration while contributing to the lightweight and miniaturization of the optical gyroscope product. Specifically, the phase modulator is arranged in the first device layer, and other optical devices are arranged in the second device layer to reduce the difficulty of preparing the integrated optical chip. In the second device layer, other optical devices except the detector are arranged in the second sub-device layer to reduce the internal loss of the integrated optical chip, which helps to improve the performance of the optical gyroscope product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0025] Figure 1 A schematic diagram of the structure of an integrated optical chip according to some embodiments of the present application;

[0026] Figure 2 for Figure 1 A schematic diagram of a cross-sectional structure of an integrated optical chip shown;

[0027] Figure 3 for Figure 1 Another schematic diagram of the cross-sectional structure of the integrated optical chip shown;

[0028] Figure 4 A schematic diagram of the structure of an integrated optical chip according to some embodiments of the present application;

[0029] Figure 5A schematic diagram of the structure of an optical gyroscope according to some embodiments of the present application;

[0030] Figures 6a to 6l A schematic diagram of the process of preparing an integrated optical chip according to some embodiments of the present application.

[0031] The reference numerals in the specific implementation manner are as follows:

[0032] 01, substrate; 02, waveguide cladding; 031, first sub-device layer; 032, second sub-device layer; 04, first device layer;

[0033] 110, input waveguide; 120, first waveguide; 130, second waveguide; 140, third waveguide; 150, fourth waveguide;

[0034] 210, a first coupler; 220, a second coupler; 230, a polarization beam splitter;

[0035] 300, detector; 310, active structure; 320, photoelectric conversion structure; 330, detector electrode;

[0036] 400, phase modulator; 410, modulation film; 420, modulator electrode;

[0037] 510. Light source; 520. Interference ring. DETAILED DESCRIPTION

[0038] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0040] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0041] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0044] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0045] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] In order to solve the problems of the prior art, the embodiments of the present application provide an integrated optical chip, a preparation method and an optical gyroscope. The integrated optical chip provided by the embodiments of the present application is first introduced below.

[0047] See also Figures 1 to 4The embodiment of the present application provides an integrated optical chip, including a first device layer 04 and a second device layer, the first device layer 04 is provided with a phase modulator 400, the phase modulator 400 includes a fourth waveguide 150 for connecting an interference ring 520; the second device layer is provided with a detection unit, the detection unit includes a first coupler 210 and a detector 300, the first coupler 210 includes a first waveguide 120, a second waveguide 130 and a third waveguide 140, the first waveguide 120 is used to connect a light source 510, the first waveguide 120 is connected to the third waveguide 140, the second waveguide 130 is connected to the third waveguide 140, the third waveguide 140 is connected to the phase modulator 400, and the second waveguide 130 is connected to the detector 300. The second device layer includes a first sub-device layer 031 and a second sub-device layer 032 , the coupling loss of the first sub-device layer 031 is greater than that of the second sub-device layer 032 , at least part of the detector 300 is located in the first sub-device layer 031 , and the first coupler 210 is located in the second sub-device layer 032 .

[0048] Specifically, the light beam enters the first coupler 210 through the first waveguide 120, and is then transmitted to the phase modulator 400 through the third waveguide 140. Signal modulation is achieved through the phase modulator 400 and is transmitted to the interference ring 520 to produce the Segnac effect. The test light beam transmitted back by the interference ring 520 enters the first coupler 210 through the third waveguide 140, and is then transmitted to the detector 300 through the second waveguide 130 to achieve conversion of optical signals into electrical signals, and then output detection results to achieve measurement of the angular velocity of the moving carrier.

[0049] Thus, the integrated optical chip integrates the detection unit and the phase modulator 400, so that the integrated optical chip can be assembled with the light source 510 and the interference ring 520 to form an optical gyroscope product, which improves the integration and helps to make the optical gyroscope product lighter and smaller. Specifically, the phase modulator 400 is arranged in the first device layer 04, and other optical devices are arranged in the second device layer to reduce the difficulty of preparing the integrated optical chip. In the second device layer, other optical devices except the detector 300 are arranged in the second sub-device layer 032 to reduce the internal loss of the integrated optical chip, which helps to improve the performance of the optical gyroscope product.

[0050] According to some embodiments of the present application, the integrated optical chip further includes a waveguide cladding 02 , the first sub-device layer 031 is located between the waveguide cladding 02 and the second sub-device layer 032 , and the refractive index of the waveguide cladding 02 is smaller than the refractive index of the first sub-device layer 031 .

[0051] Optionally, the material of the waveguide cladding 02 includes silicon dioxide.

[0052] Thus, the waveguide cladding 02 helps to confine the light to propagate in the first sub-device layer 031.

[0053] Reduce light escape, thereby reducing energy loss in integrated optical chips.

[0054] According to some embodiments of the present application, the refractive index of the second sub-device layer 032 is smaller than the refractive index of the first sub-device layer 031 , so that the second sub-device layer 032 has a lower coupling loss.

[0055] Optionally, the material of the first sub-device layer 031 is silicon, and the material of the second sub-device layer 032 is silicon nitride. Silicon nitride has the advantages of low transmission loss and low coupling loss due to its lower refractive index. However, silicon nitride, as an insulating material, cannot be used to make the active structure 310 of the detector 300. Therefore, the present application integrates other optical devices except the detector 300 into the silicon nitride layer, and arranges a silicon layer between the silicon nitride layer and the waveguide cladding 02 to prepare the active structure 310 of the detector 300, thereby improving the integration of the integrated optical chip while reducing the difficulty of preparation.

[0056] According to some embodiments of the present application, the detector 300 includes an active structure 310 and a photoelectric conversion structure 320 , which are arranged along the thickness direction of the integrated optical chip, wherein the active structure 310 is arranged in the first sub-device layer 031 .

[0057] Optionally, the photoelectric conversion structure 320 is disposed in the second sub-device layer 032 to reduce the volume of the integrated optical chip in the thickness direction.

[0058] Optionally, the material of the photoelectric conversion structure 320 includes at least one of germanium, gold, silver, aluminum, and molybdenum, and the conversion of optical signals into electrical signals is achieved by selecting materials with electro-optical properties.

[0059] Optionally, the active structure 310 includes a PN junction or a PIN junction.

[0060] It can be understood that the detector 300 further includes a detector electrode 330 exposed on the surface of the integrated optical chip to achieve interconnection between the detector 300 and other electrical devices.

[0061] Taking the silicon-germanium heterostructure as an example, the test light beam in the second waveguide 130 enters the active structure 310. Since the energy of the photon is greater than the bandgap width of the silicon-germanium alloy, the photon can be absorbed by the material and excite the electron transition in the valence band to form an electron-hole pair. The electron-hole pair can form a photocurrent in the active structure 310, which is then detected and amplified by an external electrical device through the detector electrode 330 and converted into an electrical signal output, thereby achieving the purpose of measuring the angular velocity of the moving carrier through optical interference.

[0062] According to some embodiments of the present application, please refer to Figure 3The waveguide cladding layer 02 is disposed between the first device layer 04 and the second device layer. It can be understood that the first device layer 04 and the second device layer are disposed opposite to each other to expose the phase modulator 400 and the detector electrode 330 .

[0063] According to some other embodiments of the present application, the integrated optical chip further includes a substrate 01, see Figure 2 , along the thickness direction, the first device layer 04, the second device layer, the waveguide cladding 02 and the substrate 01 are arranged in sequence.

[0064] According to some embodiments of the present application, the integrated optical chip further includes a second coupler 220 , which is disposed in the second sub-device layer 032 , and the detection unit is connected to one side of the second coupler 220 through the first waveguide 120 .

[0065] Optionally, N detection units are provided, and the N detection units are all connected to the same side of the second coupler 220 . An input waveguide 110 for connecting to the light source 510 is further provided on the other side of the second coupler 220 .

[0066] Further optionally, N is set to 2 or 3, and the second coupler 220 can be used for light splitting, so that the integrated optical chip is provided with a plurality of detection units to achieve the measurement of the angular velocity of the moving carrier along different axes.

[0067] Therefore, the light beam entering the first waveguide 120 is adjusted by the second coupler 220 to expand the application scenarios of the integrated optical chip.

[0068] Optionally, there are a first direction and a second direction intersecting each other in the plane where the second sub-device layer 032 is located, and the N detectors 300 are distributed at intervals along at least one of the first direction and the second direction.

[0069] Exemplarily, N is set to 3, and the three detectors 300 are distributed in a stepped manner to reduce the crosstalk that may occur between two adjacent detectors 300, thereby alleviating the reduction in measurement accuracy that is easily caused by integrating the detectors 300 inside the chip.

[0070] According to some embodiments of the present application, the integrated optical chip further includes a polarization beam splitter 230 , which is disposed in the second sub-device layer 032 , and the polarization beam splitter 230 is disposed upstream of the phase modulator 400 .

[0071] Optionally, the polarization beam splitter 230 may include at least one of an asymmetric directional coupler structure, a symmetric directional coupler, a multi-mode interferometer, a Mach-Zehnder interferometer, a photonic crystal polarizer, and a grating waveguide polarizer.

[0072] Optionally, the polarization beam splitter 230 is connected to the first coupler 210. Exemplarily, the polarization beam splitter 230 is connected to the first waveguide 120, or the polarization beam splitter 230 is connected to the third waveguide 140.

[0073] Optionally, the polarization beam splitter 230 is connected to the second coupler 220. Exemplarily, the polarization beam splitter 230 is connected to the input waveguide 110.

[0074] Therefore, the TE polarized light after polarization splitting is modulated and moves in the interference ring 520 to produce the Secennak effect, and the polarization beam splitter 230 is integrated in the second sub-device layer 032 to improve the integration of the integrated optical chip, which helps to miniaturize and lighten the optical gyroscope product.

[0075] It should be noted that in optical waveguides, TE polarized light usually has better transmission characteristics, including lower loss and higher mode stability. The square distribution and waveguide conditions of TE polarized light are more suitable for long-distance transmission and high-precision measurement, which is crucial for the accuracy and stability of optical gyroscopes. In actual operation, TE polarized light is relatively easy to control and keep stable. Optical gyroscopes require precise optical path and phase control, and TE polarized light provides a more stable polarization state, which helps to improve the stability and repeatability of measurements.

[0076] It can be understood that in some embodiments, the polarization beam splitter 230 is separately disposed in the optical gyroscope, the polarization beam splitter 230 is connected to the input waveguide 110, the second coupler 220 directly splits the TE polarized light, and the split sub-beams are transmitted to the interference ring 520 through the first coupler 210 and the phase modulator 400 to generate the Segnac effect to achieve the measurement of angular velocity.

[0077] According to some embodiments of the present application, the integrated optical chip further includes a light-guiding groove connected to the TM output end of the polarization beam splitter 230 .

[0078] In some embodiments, a light absorbing member is optionally provided in the light guiding groove, and the light guiding groove can absorb the TM polarized light separated from the polarization beam splitter 230. Exemplarily, the light absorbing member can be but is not limited to black epoxy resin glue, carbon black filled glue or nano material light absorbing glue.

[0079] In some other embodiments, the light guiding groove is optionally bent, and the TM polarized light is reflected multiple times in the light guiding groove and finally emitted from the end face to the outside of the integrated optical chip. The exit end of the light guiding groove is an obliquely polished end face. Exemplarily, the angle of the obliquely polished end face is 7° to 15°.

[0080] Therefore, the light-guiding groove can guide the output path of the TM polarized light output by the polarization beam splitter 230, thereby reducing the TM polarized light entering the phase modulator 400 and reducing the crosstalk of the TM polarized light to the subsequent phase modulator 400, which helps to improve the measurement accuracy of the optical gyroscope.

[0081] According to some embodiments of the present application, the phase modulator 400 includes at least one of a piezoelectric phase modulator 400 or a lithium niobate phase modulator 400 .

[0082] Optionally, the phase modulator 400 is configured as a lithium niobate phase modulator 400, including a lithium niobate film and a modulator electrode 420, and the lithium niobate is interconnected with electrical components other than the integrated optical chip through the modulator electrode 420.

[0083] Optionally, at least silicon dioxide material is included between the lithium niobate film and the second sub-device layer 032 to reduce unintended propagation of light between the second sub-device layer 032 and the lithium niobate film.

[0084] According to some embodiments of the present application, the first waveguide 120 and the third waveguide 140 are disposed on both sides of the first coupler 210 .

[0085] Optionally, the first coupler 210 is a 1×2 coupler, the first waveguide 120 and the second waveguide 130 are disposed on the same side of the first coupler 210 , and the third waveguide 140 is disposed on the other side of the first coupler 210 .

[0086] Optionally, the first coupler 210 is a circulator, the third waveguide 140 is disposed downstream of the first waveguide 120 , and the second waveguide 130 is disposed downstream of the third waveguide 140 .

[0087] Therefore, the distance between the detector 300 and the phase modulator 400 is extended without expanding the area of ​​the integrated optical chip, reducing the internal crosstalk of the integrated optical chip, which helps to improve the detection accuracy of the optical gyroscope.

[0088] According to some embodiments of the present application, the first coupler 210 further includes a fifth waveguide, the fifth waveguide is connected to the first waveguide 120, and the fifth waveguide is connected to an optical parameter meter.

[0089] Optionally, the first coupler 210 is a 2x2 coupler, the fifth waveguide and the third waveguide 140 are disposed on the same side of the first coupler 210 , and the first waveguide 120 and the second waveguide 130 are disposed on the other side of the first coupler 210 .

[0090] Optionally, the first coupler 210 is a circulator, the fifth waveguide is disposed downstream of the first waveguide 120 , the third waveguide 140 is disposed downstream of the fifth waveguide, and the second waveguide 130 is disposed downstream of the third waveguide 140 .

[0091] Therefore, the power or wavelength of the light beam output by the first waveguide 120 is measured by an optical parameter meter, thereby improving the detection accuracy of the optical gyroscope product.

[0092] Second, see Figure 5 The embodiment of the present application provides an optical gyroscope, which includes a light source 510, an interference ring 520, and an integrated optical chip provided by any of the above embodiments, wherein the light source 510 is connected to the first waveguide 120, and the interference ring 520 is connected to the fourth waveguide 150. Therefore, the optical gyroscope has all the beneficial effects of the above integrated optical chips.

[0093] Optionally, the interference ring 520 is configured as a fiber ring, or other annular structures capable of causing the light beam to undergo a Segnac effect therein.

[0094] Optionally, the light source 510 is configured as a light source 510 chip, or other carriers mounted with the light source 510, so as to be fixed relative to the integrated optical chip, thereby achieving the purpose of introducing a light beam into the integrated optical chip.

[0095] Further optionally, the light source 510 is connected to the integrated optical chip by termination.

[0096] Third, see Figures 6a to 6l The present application embodiment provides a method for preparing an integrated optical chip, which is used to prepare the integrated optical chip provided by any of the above embodiments, comprising:

[0097] S100, providing a substrate 01, and forming a waveguide cladding 02 on one side of the substrate 01;

[0098] S200, forming a patterned first dielectric layer on a side of the waveguide cladding 02 facing away from the substrate 01, wherein the first dielectric layer includes an active structure 310 of the detector 300;

[0099] S300, forming a patterned second dielectric layer on a side of the first dielectric layer away from the waveguide cladding 02, the second dielectric layer comprising a first waveguide 120, a first coupler 210, a second waveguide 130, and a third waveguide 140;

[0100] S500 , preparing a first device layer 04 , and forming a phase modulator 400 , wherein the phase modulator 400 is connected to the third waveguide 140 .

[0101] Thus, a waveguide cladding 02 and a second device layer are sequentially formed on the basis of the substrate 01, and then the phase modulator 400 is prepared, which simplifies the preparation process of the detector 300 and the phase modulator 400 in the integrated optical chip, reduces the process difficulty, and is conducive to the large-scale production of integrated optical chips.

[0102] According to some embodiments of the present application, step S100 includes:

[0103] S110, providing a substrate 01, and pre-processing one side of the substrate 01 to obtain a preset track;

[0104] S130 , preparing a waveguide cladding 02 on the side of the substrate 01 where a preset track is formed.

[0105] Optionally, in step S110, the pretreatment process is wet etching, and the etching solution includes hydrofluoric acid and nitric acid.

[0106] Optionally, in step S130, the material of the waveguide cladding 02 is silicon dioxide, and the waveguide cladding 02 is prepared by physical vapor deposition or chemical vapor deposition.

[0107] According to some embodiments of the present application, in step S200 , the material of the first dielectric layer is silicon, and the impurity concentration of the first dielectric layer is low to reduce light loss.

[0108] Optionally, in step S200 , the first dielectric layer is prepared by oxide chemical vapor deposition, and the active structure 310 is prepared by a doping process.

[0109] Optionally, in step S200, before doping begins, the first dielectric layer is pretreated, and the pretreatment includes at least one of cleaning, removing surface impurities, and pre-soaking.

[0110] Optionally, in step S200, source and drain dopants are implanted in a first temperature environment, and the first temperature environment is 1000°C to 1100°C.

[0111] Optionally, in step S200, after the source and drain dopants are implanted, a diffusion annealing process is performed in a second temperature environment, wherein the second temperature environment is 1000°C to 1100°C.

[0112] According to certain embodiments of the present application, the preparation method further comprises:

[0113] S400 , forming a photoelectric conversion structure 320 on a side of the first dielectric layer away from the waveguide cladding 02 .

[0114] Optionally, step S400 includes:

[0115] S410, forming a first protective layer on a side of the second dielectric layer away from the first dielectric layer;

[0116] S430, disposing a photoelectric shielding portion above the first protective layer, etching the first protective layer to obtain a process window, and preparing a photoelectric conversion structure 320 in the process window, wherein the thickness of the photoelectric conversion structure 320 is greater than the thickness of the second dielectric layer;

[0117] S450 , forming a second protective layer above the photoelectric conversion structure 320 , and preparing the detector electrode 330 in the second protective layer.

[0118] According to some embodiments of the present application, step S430 includes:

[0119] S431, disposing a photoelectric shielding portion above the first protective layer, and etching the first protective layer to obtain a process window to expose the active structure 310;

[0120] S432, depositing a germanium film within the process window to form a silicon-germanium heterostructure;

[0121] S433, providing a third temperature environment to allow the germanium film to grow germanium crystals within the process window.

[0122] Optionally, in step S432 , a silicon-germanium heterostructure is formed by chemically reacting the germanium film with the silicon material of the first dielectric layer.

[0123] Optionally, in step S433, a third temperature environment is provided by a titanium nitride heating electrode, and the growth rate and crystal quality of the germanium crystal are adjusted by controlling the temperature of the heating electrode.

[0124] According to some embodiments of the present application, step S450 includes:

[0125] S451, forming a second protective layer above the photoelectric conversion structure 320, providing a shielding portion of the detector electrode 330 above the second protective layer, and etching the second protective layer to obtain a contact hole;

[0126] S453 , forming a detector electrode 330 in the contact hole, wherein the detector electrode 330 is electrically connected to at least a portion of the photoelectric conversion structure 320 .

[0127] Optionally, in step S453 , tungsten material and gold electrodes are filled in the contact holes to form detector electrodes 330 .

[0128] According to some embodiments of the present application, step S500 includes:

[0129] S510, forming an electro-optical material layer;

[0130] S530, an electro-optic shielding portion is provided on a side of the electro-optic material layer away from the waveguide cladding 02, and the electro-optic material layer is etched to obtain a modulation film 410;

[0131] S550 , forming a modulator electrode 420 on the side of the modulation film 410 away from the waveguide cladding 02 .

[0132] Optionally, in step S510, the electro-optic material layer is formed by bonding. When the bonding surface is sufficiently flat and clean, the two can be connected based on the action of chemical bonds such as van der Waals force or hydrogen bond. If the bonding surface is adhered, the physical force can be converted into the force between chemical bonds through a high temperature annealing process to enhance the bonding strength.

[0133] According to some embodiments of the present application, step S510 includes:

[0134] S510A, etching and removing the substrate 01, and forming an electro-optic material layer on the side of the waveguide cladding 02 away from the second device layer.

[0135] According to some embodiments of the present application, step S510 includes:

[0136] S510B, forming an electro-optic material layer on a side of the second device layer facing away from the waveguide cladding 02.

[0137] According to some embodiments of the present application, step S530 includes:

[0138] S531, design the electro-optical shielding part;

[0139] S533, heating the electro-optic material layer to cause the electro-optic material layer to generate permanent polarization and improve crystal quality;

[0140] S535, etching the polarized electro-optical material layer to obtain a modulation film 410;

[0141] S537 , grinding and polishing the modulated film 410 .

[0142] Optionally, in step S533, the heating temperature is between 1000°C and 1200°C.

[0143] According to some embodiments of the present application, step S550 includes:

[0144] S551, preparing an electrode metal solution;

[0145] S553, depositing a modulator electrode 420 on the side of the modulation film 410 away from the waveguide cladding 02;

[0146] S555 , coating a non-conductive layer on the side of the modulator electrode 420 facing away from the modulation film 410 .

[0147] Optionally, step S550 further includes:

[0148] S557A, etch the non-conductive layer to expose the modulator electrode 420.

[0149] Optionally, step S550 further includes:

[0150] S557B, etching the non-conductive layer to expose the modulator electrode 420 and the detector electrode 330.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An integrated optical chip, characterized in that: The invention comprises a first device layer and a second device layer, wherein the first device layer is provided with a phase modulator, wherein the phase modulator comprises a fourth waveguide for connecting an interference ring, and the second device layer is provided with a detection unit, wherein the detection unit comprises: A first coupler comprises a first waveguide, a second waveguide and a third waveguide, wherein the first waveguide is used to connect to a light source, the first waveguide is connected to the third waveguide, the second waveguide is connected to the third waveguide, and the third waveguide is connected to the phase modulator; a detector connected to the second waveguide; Among them, the second device layer includes a first sub-device layer and a second sub-device layer, the coupling loss of the first sub-device layer is greater than that of the second sub-device layer, at least part of the detector is located in the first sub-device layer, the first coupler is located in the second sub-device layer, the light beam is transmitted to the phase modulator through the first waveguide and the third waveguide, and is transmitted to the interference ring through the phase modulator, and the test light beam returned by the interference ring is transmitted to the detector through the third waveguide and the second waveguide.

2. The integrated optical chip according to claim 1, characterized in that: The integrated optical chip also includes a waveguide cladding, the first sub-device layer is located between the waveguide cladding and the second sub-device layer, the material of the first sub-device layer includes at least one of silicon, gallium arsenide, and indium phosphide, and the material of the second sub-device layer includes silicon nitride.

3. The integrated optical chip according to claim 2, characterized in that: The detector includes an active structure and a photoelectric conversion structure, wherein the active structure is located in the first sub-device layer, the active structure includes a PN junction or a PIN junction, and the photoelectric conversion structure includes at least one of germanium, gold, silver, aluminum, and molybdenum.

4. The integrated optical chip according to claim 2, characterized in that: Along the thickness direction, the waveguide cladding is arranged between the first device layer and the second device layer, or, along the thickness direction, the second device layer is arranged between the first device layer and the waveguide cladding, and a substrate is arranged on the side of the waveguide cladding away from the second device layer.

5. The integrated optical chip according to claim 1, characterized in that: The integrated optical chip further includes a second coupler disposed in the second sub-device layer. The detection units are provided with N pieces, and the N first waveguides are connected to the second couplers. The second coupler further includes an input waveguide, and the input waveguide is used to connect to a light source.

6. The integrated optical chip according to claim 5, characterized in that: The integrated optical chip further includes a polarization beam splitter disposed on the second sub-device layer, the polarization beam splitter is used to obtain TE polarized light, and the polarization beam splitter is connected to the first coupler or the second coupler.

7. The integrated optical chip according to claim 6, characterized in that: The integrated optical chip further comprises a light guiding groove, wherein the light guiding groove is connected to the TM output end of the polarization beam splitter, wherein a light absorbing member is arranged in the light guiding groove, or the output end of the light guiding groove is an obliquely polished end face.

8. An optical gyroscope, characterized in that: include: light source; The integrated optical chip according to any one of claims 1 to 7, wherein the light source is connected to the first waveguide, An interference ring is connected to the phase modulator.

9. A method for preparing an integrated optical chip, characterized in that: include: providing a substrate, and forming a waveguide cladding on one side of the substrate; forming a patterned first dielectric layer on a side of the waveguide cladding away from the substrate, the first dielectric layer including an active structure of the detector; A patterned second dielectric layer is formed on a side of the first dielectric layer away from the waveguide cladding, wherein the second dielectric layer includes a first coupler, a first waveguide, a second waveguide, and a third waveguide; A first device layer is prepared to form a phase modulator, and the phase modulator is connected to the third waveguide.

10. The method for preparing an integrated optical chip according to claim 9, characterized in that: The integrated optical chip preparation method further comprises: forming a first protective layer on a side of the second dielectric layer facing away from the first dielectric layer; A first shielding portion is provided above the first protective layer, and the first protective layer and the second dielectric layer are etched to expose the active structure of the detector; forming a photoelectric conversion structure above the active structure, wherein the thickness of the photoelectric conversion structure is greater than the thickness of the second dielectric layer; A second protective layer is formed above the photoelectric conversion structure, a second shielding portion is arranged above the second protective layer, the second protective layer is etched to obtain a contact hole, a detector electrode is formed in the contact hole, and the detector electrode is electrically connected to at least part of the photoelectric conversion structure.

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