Two-dimensional grating coupler

Abstract

The invention provides a two-dimensional grating coupler, and relates to the field of photoelectric integration and the technical field of optical communication. The two-dimensional grating coupler comprises a silicon waveguide layer used for receiving optical signals, respectively coupling the optical signals according to a first optical field coupling coefficient and a second optical field coupling coefficient to obtain a first coupled optical signal and a second coupled optical signal, and respectively outputting the first coupled optical signal and the second coupled optical signal along a first direction and a second direction; the first organic electro-optical material layer is arranged above the silicon waveguide layer, and a first electrode pair is arranged in the first organic electro-optical material layer; and the second organic electro-optical material layer is arranged below the silicon waveguide layer, and a second electrode pair is arranged in the second organic electro-optical material layer. According to the embodiment of the invention, the organic electro-optical materials are respectively bonded on the upper layer and the lower layer of the silicon waveguide layer, and the electrode pairs which can be independently driven are arranged in all directions, so that the real-time adjustment of the optical field coupling coefficient is realized, and the coupling efficiency is remarkably improved.

Description

Technical Field

[0001] The present disclosure relates to the fields of optoelectronic integration and optical communication technology, and in particular to a two-dimensional grating coupler. Background Art

[0002] Integrated silicon-based photonics systems have become a core platform for high-speed optical interconnects due to their high bandwidth, low crosstalk, and compatibility with CMOS processes. Grating couplers, as key interfaces for on-chip optical input / output, are widely used for chip-level optoelectronic system testing and signal transmission due to their advantages such as small size and planar coupling.

[0003] However, traditional silicon-based grating couplers face two major bottlenecks: first, mode field mismatch. The Gaussian mode field of a single-mode fiber is difficult to match with the grating's diffraction field, significantly reducing coupling efficiency. Existing solutions rely on custom gratings for fibers with varying core diameters. These static gratings require high manufacturing precision and are complex to fabricate. Once fabricated, they cannot dynamically compensate for temperature drift, manufacturing variations, or changes in fiber mode size.

[0004] The second is polarization sensitivity. The one-dimensional grating coupler can only efficiently couple a single polarization state (such as TE mode), and the coupling efficiency for orthogonal polarization states (TM mode) drops sharply. Summary of the Invention

[0005] In view of the above problems, embodiments of the present disclosure provide a two-dimensional grating coupler to solve the problems of polarization sensitivity and low efficiency of existing grating couplers.

[0006] One aspect of the present disclosure provides a two-dimensional grating coupler, characterized by comprising:

[0007] The silicon waveguide layer is configured to receive an optical signal and couple the optical signal according to a first optical field coupling coefficient and a second optical field coupling coefficient to obtain a first coupled optical signal and a second coupled optical signal, and then output the first coupled optical signal and the second coupled optical signal along a first direction and a second direction, respectively, wherein inverse extensions of the first direction and the second direction are perpendicular to each other. A first organic electro-optical material layer is disposed above the silicon waveguide layer, wherein a plurality of first electrodes are disposed on two sides of the first organic electro-optical material layer parallel to the first direction, wherein any first electrode on one side of the two sides is combined with a first electrode on the other side to form a first electrode pair, and the first electrode pair is configured to adjust the first optical field coupling coefficient. A second organic electro-optical material layer is disposed below the silicon waveguide layer, wherein a plurality of second electrodes are disposed on two sides of the second organic electro-optical material layer parallel to the second direction, wherein any second electrode on one side of the two sides is combined with a second electrode on the other side to form a second electrode pair, and the second electrode pair is configured to adjust the second optical field coupling coefficient.

[0008] According to an embodiment of the present disclosure, the spacings between the multiple first electrodes on the same side are all the same; the spacings between the multiple second electrodes on the same side are all the same.

[0009] According to an embodiment of the present disclosure, the first organic photoelectric material layer includes a plurality of first organic electro-optical rectangular structures, and the width of the first organic photoelectric rectangular structure is less than or equal to the width of the first electrode; the second organic photoelectric material layer includes a plurality of second organic electro-optical rectangular structures, and the width of the second organic photoelectric rectangular structure is less than or equal to the width of the second electrode.

[0010] According to an embodiment of the present disclosure, a silicon waveguide layer includes: an output waveguide, a transition waveguide and a two-dimensional grating, wherein the two-dimensional grating is in contact with a plurality of first organic electro-optical rectangular structures and a plurality of second organic electro-optical rectangular structures; wherein the short end face of the transition waveguide is connected to the output waveguide, the long end face of the transition waveguide is connected to the two-dimensional grating, and the width of the transition waveguide gradually narrows along the two-dimensional grating toward the output waveguide.

[0011] According to an embodiment of the present disclosure, the width, height, grating period and duty cycle of the two-dimensional grating along different directions are all the same, and the shapes of the two-dimensional grating include circular and square.

[0012] According to an embodiment of the present disclosure, the first organic electro-optical material rectangular structure is above the unetched portion of the two-dimensional grating, filled along the second direction and periodically arranged along the first direction; the second organic electro-optical material rectangular structure is below the unetched portion of the two-dimensional grating, filled along the first direction and periodically arranged along the second direction.

[0013] According to an embodiment of the present disclosure, the two-dimensional grating coupler further includes: a first reflective layer disposed above the first organic optoelectronic material layer, the first reflective layer being configured to couple an optical signal to the silicon waveguide layer and to reflect a portion of the optical signal reflected by the silicon waveguide layer to above the silicon waveguide layer back to the silicon waveguide layer.

[0014] According to an embodiment of the present disclosure, the two-dimensional grating coupler further includes: a coupling optical fiber disposed above the first reflective layer, the coupling optical fiber being used to transmit the optical signal to the silicon waveguide layer.

[0015] According to an embodiment of the present disclosure, the two-dimensional grating coupler further includes: a protective layer, which is provided above the first reflective layer, the first organic electro-optical material layer and the silicon waveguide layer.

[0016] According to an embodiment of the present disclosure, the two-dimensional grating coupler further includes: a second reflective layer, disposed below the second organic electro-optical material layer, the second reflective layer being configured to reflect a portion of the optical signal reflected by the silicon waveguide layer to the bottom of the silicon waveguide layer back to the silicon waveguide layer.

[0017] The embodiments of the present disclosure bond organic electro-optical materials to the upper and lower layers of the silicon waveguide layer, respectively, and arrange independently drivable electrode pairs in each direction. The device of the present disclosure can adjust the light field coupling coefficient in real time during device operation, achieving precise matching of the two-dimensional profile of the diffracted light field without the need for device replacement or re-etching, significantly improving coupling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0019] Figure 1 Schematically shows a structural diagram of a grating coupling portion according to an embodiment of the present disclosure;

[0020] Figure 2 Schematically shows a structural diagram of a first organic electro-optical material layer according to an embodiment of the present disclosure;

[0021] Figure 3 Schematically shows a structural diagram of a second organic electro-optical material layer according to an embodiment of the present disclosure;

[0022] Figure 4 Schematically shows a structural diagram of a silicon waveguide layer according to an embodiment of the present disclosure;

[0023] Figure 5 The structure of a two-dimensional grating coupler according to an embodiment of the present disclosure is schematically shown.

[0024] [Description of Reference Numerals]

[0025] 1-first organic electro-optical material layer; 101-first electrode; 102-first organic electro-optical rectangular structure; 2-silicon waveguide layer; 201-output waveguide; 202-transition waveguide; 203-two-dimensional grating; 3-second organic electro-optical material layer; 301-second electrode; 302-second organic electro-optical rectangular structure; 4-first reflective layer; 5-coupling optical fiber; 6-second reflective layer; 7-protective layer; 8-substrate. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0027] It should be noted that in the drawings or descriptions of the specification, similar or identical parts use the same figure numbers. The technical features in the various embodiments exemplified in the specification can be freely combined to form new solutions without conflict. In addition, each claim can be used as an embodiment alone or the technical features in each claim can be combined as a new embodiment. In the drawings, the shape or thickness of the embodiment can be expanded and simplified or conveniently indicated. Furthermore, the elements or implementations not shown or described in the drawings are forms known to ordinary technicians in the relevant technical field. In addition, although this article may provide demonstrations of parameters containing specific values, it should be understood that the parameters do not need to be exactly equal to the corresponding values, but can be approximated to the corresponding values ​​within an acceptable error tolerance or design constraint.

[0028] Unless there are technical obstacles or contradictions, the above-mentioned various embodiments of the present disclosure can be freely combined to form additional embodiments, and these additional embodiments are all within the protection scope of the present disclosure.

[0029] Although the present disclosure is described in conjunction with the accompanying drawings, the embodiments disclosed in the drawings are intended to illustrate preferred embodiments of the present disclosure and are not to be construed as limiting the present disclosure. The dimensional ratios in the drawings are merely illustrative and are not to be construed as limiting the present disclosure.

[0030] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined in the claims and their equivalents.

[0031] Figure 1 The structure of the grating coupling part according to an embodiment of the present disclosure is schematically shown.

[0032] like Figure 1As shown, an embodiment of the present disclosure provides a two-dimensional grating coupler, characterized by comprising: a silicon waveguide layer 2, configured to receive an optical signal and couple the optical signal according to a first optical field coupling coefficient and a second optical field coupling coefficient to obtain a first coupled optical signal and a second coupled optical signal, and then output the first coupled optical signal and the second coupled optical signal along a first direction and a second direction, respectively, wherein the inverse extension lines of the first direction and the second direction are perpendicular to each other; a first organic electro-optical material layer 1, disposed above the silicon waveguide layer, wherein a plurality of first electrodes 101 are disposed on both sides of the first organic electro-optical material layer parallel to the first direction, wherein any first electrode 101 on one side of the two sides is combined with a first electrode 101 on the other side to form a first electrode pair, and the first electrode pair is used to adjust the first optical field coupling coefficient; and a second organic electro-optical material layer 3, disposed below the silicon waveguide layer, wherein a plurality of second electrodes 301 are disposed on both sides of the second organic electro-optical material layer parallel to the second direction, wherein any second electrode 301 on one side of the two sides is combined with a second electrode 301 on the other side to form a second electrode pair, and the second electrode pair is used to adjust the second optical field coupling coefficient.

[0033] In some embodiments, the materials of the first organic electro-optical material layer 1 and the second organic electro-optical material layer 3 are both organic electro-optical materials with a side chain / host-guest system, including, for example, PMMA+DR1, PMMA+YLD124, PMMA+DLD164, and PVT copolymers with a side chain / host-guest system. Other organic electro-optical materials, such as HLD1 / HLD2 materials, may also be used, and the embodiments of the present disclosure are not limited thereto. The thickness of the first organic electro-optical material layer 1 and the second organic electro-optical material layer 3 may be 0.1 μm to 2 μm.

[0034] The organic electro-optical material has excellent electro-optical performance. To utilize the maximum electro-optic coefficient r33 of the organic electro-optical material, the r33 direction of the organic electro-optical material in the first organic electro-optical material layer 1 is the same as the second direction, and the r33 direction of the organic electro-optical material in the second organic electro-optical material layer 3 is the same as the first direction.

[0035] The organic electro-optical material selected in the embodiments of the present disclosure is a side chain / host-guest system, which can be integrated by spin coating or bonding in a standard CMOS process, and can be seamlessly connected with the metal interconnection, electrode preparation and other steps in the silicon photonic platform, thereby reducing the overall manufacturing cost.

[0036] Figure 2 The structure of the first organic electro-optical material layer according to an embodiment of the present disclosure is schematically shown. Figure 3 Schematic diagram showing the structure of the second organic electro-optical material layer according to an embodiment of the present disclosure

[0037] In some embodiments, as Figure 2 and Figure 3As shown, the x-axis direction marked in the figure is used as the first direction, and the y-axis direction marked in the figure is used as the second direction. The spacing between the multiple first electrodes on the same side is the same; the spacing between the multiple second electrodes on the same side is the same.

[0038] The length, width, and position of the first electrodes 101 and the second electrodes 301 can be flexibly designed based on the structure of the two-dimensional grating 203. The spacing between the multiple first electrodes 101 and the multiple second electrodes 301 should be minimized without affecting light absorption to improve modulation efficiency. The number of first electrode pairs and second electrode pairs should at least ensure that the entire length and width of the two-dimensional grating 203 are covered.

[0039] Please continue reading Figure 2 and Figure 3 In some embodiments, the first organic photoelectric material layer 1 includes a plurality of first organic electro-optical rectangular structures 102, and the width of the first organic photoelectric rectangular structure 102 is less than or equal to the width of the first electrode 101; the second organic photoelectric material layer 3 includes a plurality of second organic electro-optical rectangular structures 302, and the width of the second organic photoelectric rectangular structure 302 is less than or equal to the width of the second electrode 301.

[0040] In some embodiments, the first organic electro-optical material rectangular structure 102 is above the unetched portion of the two-dimensional grating 203, filled along the second direction and periodically arranged along the first direction; the second organic electro-optical material rectangular structure 302 is below the unetched portion of the two-dimensional grating 203, filled along the first direction and periodically arranged along the second direction.

[0041] Figure 4 The structure of a silicon waveguide layer according to an embodiment of the present disclosure is schematically shown.

[0042] According to the embodiments of the present disclosure, Figure 4 As shown, the x-axis direction marked in the figure is used as the first direction, and the y-axis direction marked in the figure is used as the second direction. The silicon waveguide layer in the embodiment of the present disclosure includes: an output waveguide 201, a transition waveguide 202, and a two-dimensional grating 203. The two-dimensional grating 203 is in contact with the plurality of first organic electro-optical rectangular structures 102 and the plurality of second organic electro-optical rectangular structures 302. The short end face of the transition waveguide 202 is connected to the output waveguide 201, and the long end face of the transition waveguide 202 is connected to the two-dimensional grating 203. The width of the transition waveguide 202 gradually narrows along the two-dimensional grating 203 toward the output waveguide 201.

[0043] In some embodiments, the embodiments of the present disclosure do not limit the shapes of the transition waveguide 202 and the output waveguide 201 , and relevant personnel in this field can make corresponding adjustments to obtain the required device size.

[0044] In some embodiments, the width, height, grating period, and duty cycle of the two-dimensional grating 203 along different directions are all the same. The shapes of the two-dimensional grating 203 include circular and square. The duty cycle of the two-dimensional grating 203 can range from 0.3 to 0.7, and the etching depth of the two-dimensional grating 203 can range from 20% to 100% of the total thickness of the silicon waveguide layer 2. The thickness of the silicon waveguide layer 2 can range from 0.1 μm to 1 μm, and the width of the two-dimensional grating 203 can range from 1.5 μm to 15 μm. The grating period of the two-dimensional grating 203 can range from 0.5 μm to 1.5 μmm.

[0045] Figure 5 The structure of a two-dimensional grating coupler according to an embodiment of the present disclosure is schematically shown.

[0046] In some embodiments, as Figure 5 As shown, the two-dimensional grating coupler in the embodiment of the present application further includes: a first reflective layer 4, which is arranged above the first organic optoelectronic material layer 1, and the first reflective layer 4 is used to couple the optical signal to the silicon waveguide layer 2, and reflect part of the optical signal reflected by the silicon waveguide layer 2 to the top of the silicon waveguide layer 2 back to the silicon waveguide layer 2.

[0047] In some embodiments, the first reflective layer 4 may include two reflective layers. The above number of reflective layers is only for example. It should be ensured that the number of reflective layers in the first reflective layer is greater than or equal to two.

[0048] According to an embodiment of the present disclosure, the two-dimensional grating coupler in the embodiment of the present application further includes: a coupling optical fiber 5, which is arranged above the first reflective layer 4, and the coupling optical fiber 5 is used to transmit the optical signal to the silicon waveguide layer 2.

[0049] Please continue reading Figure 5 In some embodiments, the coupling optical fiber 5 is disposed above the first reflective layer 4 , and a projection of the incident direction of the coupling optical fiber 5 within the plane where the first direction and the second direction are located is located within the second quadrant.

[0050] In the disclosed embodiment, a voltage adjustment device can also be used to determine the fiber mode field distribution based on the size and position of the coupling fiber 5, thereby determining the voltage between the two first electrodes 101 of the first organic electro-optical material layer 1 and the target voltage between the two second electrodes 301 of the second organic electro-optical material layer 3. The voltage between the two first electrodes 101 of the first organic electro-optical material layer 1 and the voltage between the two second electrodes 301 of the second organic electro-optical material layer 3 are adjusted so that the first electrode 101 and the second electrode 301 pair can change the effective refractive index of the two-dimensional grating 203 through the electro-optic effect, thereby changing the coupling coefficient of the diffracted light field of the two-dimensional grating 203.

[0051] The voltages of the two first electrodes 101 of the first organic electro-optical material layer 1 and the two second electrodes 301 of the second organic electro-optical material layer 3 can also be dynamically adjusted according to the diameter, tilt angle and position of the coupling optical fiber 5, so as to adjust the refractive index of the first organic electro-optical material rectangular structure 102 and the second organic electro-optical material rectangular structure 302, thereby changing the refractive index of the two-dimensional grating 203 along the first direction and the second direction, and then adjusting the coupling coefficient of the diffraction light field of the two-dimensional grating 203 along the first direction and the second direction, so that its diffraction mode field distribution matches the mode field of the coupling optical fiber 5 as much as possible, thereby improving the coupling efficiency of the grating coupler.

[0052] Specifically, when the diameter, tilt angle, and position of the coupling optical fiber 5 change, the coupling coefficients of the various portions of the coupling grating 5 in the first and second directions can be adjusted by redistributing the voltages between the first electrode pair of the first organic electro-optical material layer 1 and the second electrode pair of the second organic electro-optical material layer 3, thereby improving the coupling efficiency. In practical applications, the voltage adjustment mechanism can sequentially adjust the voltage applied between the first electrode pair and the voltage applied between the second electrode pair based on the actual position and tilt angle of the coupling optical fiber 5, while simultaneously measuring the intensity of the optical fiber output light. When the coupled light is strongest, the voltages applied between the first electrode pair and the voltage applied between the second electrode pair are the target voltages.

[0053] In a possible embodiment, the coupling grating 5 may also be a non-uniform grating, that is, the width, height, grating period and duty cycle of the coupling grating 5 along different directions may be different.

[0054] Please continue reading Figure 5 According to an embodiment of the present disclosure, the two-dimensional grating coupler further includes: a protective layer 7 , which is disposed above the first reflective layer 4 , the first organic electro-optical material layer 1 and the silicon waveguide layer 2 .

[0055] Please continue reading Figure 5 The two-dimensional grating coupler in the embodiment of the present application further includes: a second reflective layer 6, which is arranged below the second organic electro-optical material layer 3, and the second reflective layer 6 is used to reflect part of the light signal reflected by the silicon waveguide layer 2 to the bottom of the silicon waveguide layer 2 back to the silicon waveguide layer 2.

[0056] In some embodiments, the second reflective layer 6 is disposed on the surface of the substrate 8 , and the second reflective layer 6 may be a metal reflector or a distributed Bragg reflector.

[0057] It should be understood that the specific order or hierarchy of steps in the disclosed processes is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in an exemplary order and are not intended to be limited to a specific order or hierarchy.

[0058] It should also be noted that directional terms such as "upper," "lower," "front," "back," "left," and "right" mentioned in the embodiments are merely references to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, identical elements are represented by identical or similar reference numerals. Conventional structures or configurations that may cause confusion in understanding this disclosure will be omitted. Furthermore, the shapes, sizes, and positional relationships of the components in the drawings do not reflect their actual sizes, proportions, or actual positional relationships.

[0059] In the foregoing detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the disclosure comprises less than all features of any individual disclosed embodiment. The appended claims are therefore hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the disclosure.

[0060] In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. With respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", as explained in terms of "including" used as a transitional word in the claims. Any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0061] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A two-dimensional grating coupler, characterized in that: include: a silicon waveguide layer for receiving an optical signal, coupling the optical signal according to a first optical field coupling coefficient and a second optical field coupling coefficient to obtain a first coupled optical signal and a second coupled optical signal, and outputting the first coupled optical signal and the second coupled optical signal along a first direction and a second direction, respectively, wherein the reverse extension lines of the first direction and the second direction are perpendicular to each other; a first organic electro-optical material layer disposed above the silicon waveguide layer, wherein a plurality of first electrodes are disposed on two sides of the first organic electro-optical material layer parallel to the first direction, wherein any first electrode on one of the two sides is combined with a first electrode on the other side to form a first electrode pair, and the first electrode pair is used to adjust the first light field coupling coefficient; A second organic electro-optical material layer is disposed below the silicon waveguide layer. A plurality of second electrodes are disposed on both sides of the second organic electro-optical material layer parallel to the second direction. Any second electrode on one of the two sides is combined with a second electrode on the other side to form a second electrode pair. The second electrode pair is used to adjust the second light field coupling coefficient.

2. The two-dimensional grating coupler according to claim 1, characterized in that The spacing between the plurality of first electrodes on the same side is the same; The intervals between the plurality of second electrodes on the same side are all the same.

3. The two-dimensional grating coupler according to claim 1, characterized in that The first organic photoelectric material layer includes a plurality of first organic electro-optical rectangular structures, and the width of the first organic photoelectric rectangular structure is less than or equal to the width of the first electrode; The second organic photoelectric material layer includes a plurality of second organic photoelectric rectangular structures, and the width of the second organic photoelectric rectangular structure is less than or equal to the width of the second electrode.

4. The two-dimensional grating coupler according to claim 3, characterized in that The silicon waveguide layer includes: an output waveguide, a transition waveguide and a two-dimensional grating, wherein the two-dimensional grating is in contact with the plurality of the first organic electro-optical rectangular structures and the plurality of the second organic electro-optical rectangular structures; The short end face of the transition waveguide is connected to the output waveguide, the long end face of the transition waveguide is connected to the two-dimensional grating, and the width of the transition waveguide gradually narrows along the two-dimensional grating toward the output waveguide.

5. The two-dimensional grating coupler according to claim 4, characterized in that: The width, height, grating period and duty cycle of the two-dimensional grating along different directions are all the same, and the shape of the two-dimensional grating includes circle and square.

6. The two-dimensional grating coupler according to claim 4, characterized in that: The first organic electro-optical material rectangular structure is located above the unetched portion of the two-dimensional grating, is filled along the second direction, and is periodically arranged along the first direction; The second organic electro-optical material rectangular structures are below the unetched portion of the two-dimensional grating, filling along the first direction and periodically arranged along the second direction.

7. The two-dimensional grating coupler according to claim 1, characterized in that The two-dimensional grating coupler further includes: A first reflective layer is disposed above the first organic photoelectric material layer, and is used to couple the optical signal to the silicon waveguide layer and reflect a portion of the optical signal reflected by the silicon waveguide layer to above the silicon waveguide layer back to the silicon waveguide layer.

8. The two-dimensional grating coupler according to claim 7, characterized in that: The two-dimensional grating coupler further includes: A coupling optical fiber is disposed above the first reflective layer, and is used to transmit the optical signal to the silicon waveguide layer.

9. The two-dimensional grating coupler according to claim 7, characterized in that: The two-dimensional grating coupler further includes: The protective layer is disposed above the first reflective layer, the first organic electro-optical material layer and the silicon waveguide layer.

10. The two-dimensional grating coupler according to claim 1, characterized in that The two-dimensional grating coupler further includes: The second reflective layer is disposed below the second organic electro-optical material layer, and is used to reflect part of the optical signal reflected by the silicon waveguide layer to the bottom of the silicon waveguide layer back to the silicon waveguide layer.

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