All-optical switch and preparation method thereof

Abstract

The invention provides an all-optical switch and a preparation method thereof, and belongs to the technical field of communication. The all-optical switch provided by the invention comprises a substrate layer 100, a waveguide core layer constructed on the upper surface of the substrate layer 100 and an upper wrapping layer 600 wrapping the outside of the waveguide core layer, the waveguide core layer is an asymmetric Mach-Zehnder interferometer type 1 * 33D waveguide core layer, and the refractive index of the waveguide core layer is higher than that of the substrate layer 100 and that of the upper wrapping layer 600; the waveguide core layer is sequentially divided into an input region 200, a first coupling region 300, a second coupling region 400 and a 3D output region 500 along a light incidence direction; a composite buried layer 302 is arranged in the waveguide core layer in the first coupling region 300, and the composite buried layer 302 comprises a polymer matrix and nanoparticles doped in the polymer matrix. The all-optical switch is compact in structure, and has the characteristics of low power consumption, low loss and quick response.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an all-optical switch and a preparation method thereof. Background Art

[0002] With the rapid development of optical communication technology, traditional electronic devices are gradually unable to meet the needs of high-speed and large-capacity data transmission. Photonic technology has become an important development direction in the future communication field due to its advantages of high bandwidth and low loss. In photonic integrated circuits, all-optical switches are one of the core components, and their performance can directly affect the speed and power consumption of photonic systems.

[0003] Existing all-optical switching technologies are mostly based on two-dimensional (2D) planar photonic structures, which can integrate multiple photonic devices in a single plane to achieve modulation, branching and switching of optical signals. For example, in silicon-based waveguides, the nonlinear optical properties of silicon materials are utilized to integrate efficient photothermal or photoelectric effect materials to achieve fast response of all-optical switches, which are compatible with existing CMOS processes. However, the nonlinear coefficient of silicon materials is relatively low, which limits the application of silicon-based all-optical switches in low-power photonic devices. In recent years, graphene has attracted much attention for its unique optoelectronic properties. Integrating graphene into two-dimensional photonic structures, such as depositing graphene layers on silicon waveguides, can achieve fast optical modulation and signal switching. However, large-scale manufacturing of graphene layers still faces challenges. In addition, the light absorption properties of graphene will lead to increased insertion loss of the device, thereby affecting the transmission efficiency of optical signals. Summary of the invention

[0004] The object of the present invention is to provide an all-optical switch and a method for preparing the same. The all-optical switch provided by the present invention has a compact structure, is easy to integrate, and has the characteristics of low power consumption, low loss and fast response.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides an all-optical switch, comprising a substrate layer 100, a waveguide core layer constructed on the upper surface of the substrate layer 100, and an upper cladding layer 600 coated on the outside of the waveguide core layer, wherein the waveguide core layer is an asymmetric Mach-Zehnder interferometer type 1×33D waveguide core layer, and the refractive index of the waveguide core layer is higher than that of the substrate layer 100 and the upper cladding layer 600;

[0007] Along the light incident direction, the waveguide core layer is sequentially divided into an input region 200, a first coupling region 300, a second coupling region 400 and a 3D output region 500;

[0008] A composite buried layer 302 is disposed inside the waveguide core layer located in the first coupling region 300 . The composite buried layer 302 includes a polymer matrix and nanoparticles doped in the polymer matrix. The polymer matrix and the nanoparticles are made of different materials.

[0009] Preferably, based on the upper surface of the base layer 100, the waveguide core layer is sequentially provided with a first waveguide layer, a second waveguide layer and a third waveguide layer from bottom to top, the first waveguide layer includes a first waveguide layer a and a first waveguide layer c, the second waveguide layer includes a second waveguide layer a, and the third waveguide layer includes a third waveguide layer b;

[0010] The first waveguide a and the second waveguide a are both located in the input area 200, the first coupling area 300, the second coupling area 400 and the 3D output area 500, and the first waveguide a and the second waveguide a located in the input area 200 have a 3D asymmetric Mach-Zehnder interferometer structure, the composite buried layer 302 is arranged between the first waveguide a and the second waveguide a located in the first coupling area 300, and the first waveguide a and the second waveguide a located in the second coupling area 400 and the 3D output area 500 are stacked;

[0011] The third layer waveguide b is located in the second coupling region 400 and the 3D output region 500, and the third layer waveguide b does not contact the second layer waveguide a. Along the light incident direction, the projection area of ​​the starting end of the third layer waveguide b located in the second coupling region 400 covers the second layer waveguide a below, and the projection area of ​​the third layer waveguide b located in the 3D output region 500 does not cover the second layer waveguide a.

[0012] The first layer waveguide c is located in the first coupling area 300, the second coupling area 400 and the 3D output area 500, and the first layer waveguide c is not in contact with the first layer waveguide a, and the projection area of ​​the third layer waveguide b located in the 3D output area 500 and the first layer waveguide c are respectively located on both sides of the first layer waveguide a.

[0013] Preferably, the waveguide core layer located in the input area 200 includes a 1+2 layer straight waveguide 1a 201, a 1 layer S-bend waveguide 1a 202, a 2 layer S-bend waveguide 1a 203, a 1 layer coupled arm waveguide a 204, a 2 layer coupled arm waveguide a 205, a 1 layer S-bend waveguide 2a 206, a 2 layer S-bend waveguide 2a 207 and a 1+2 layer straight waveguide 2a 208;

[0014] The 1+2 layer straight waveguide 1a 201 includes a 1st layer straight waveguide 1a and a 2nd layer straight waveguide 1a stacked sequentially from bottom to top, and the 1+2 layer straight waveguide 2a 208 includes a 1st layer straight waveguide 2a and a 2nd layer straight waveguide 2a stacked sequentially from bottom to top;

[0015] The first layer of straight waveguide 1a, the first layer of S-bend waveguide 1a 202, the first layer of coupled arm waveguide a 204, the first layer of S-bend waveguide 2a 206 and the first layer of straight waveguide 2a are connected in sequence;

[0016] The second layer straight waveguide 1a, the second layer S-bend waveguide 1a 203, the second layer coupled arm waveguide a 205, the second layer S-bend waveguide 2a 207 are sequentially connected to the second layer straight waveguide 2a.

[0017] Preferably, the waveguide core layer located in the first coupling region 300 includes a 1+2 layer straight waveguide 3a 301 and a 1 layer straight waveguide 3c 303;

[0018] The 1+2 layer straight waveguide 3a 301 includes a 1st layer straight waveguide 3a, a composite buried layer 302 and a 2nd layer straight waveguide 3a stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 3a 301 is connected to the 1+2 layer output straight waveguide 2a208.

[0019] Preferably, the waveguide core layer located in the second coupling region 400 includes a 1+2 layer straight waveguide 4a 401, a 3 layer straight waveguide 4b 402, a 3 layer S-bend waveguide 4b 403, a 1 layer S-bend waveguide 4c 404 and a 1 layer straight waveguide 4c 405;

[0020] The 1+2 layer straight waveguide 4a401 includes a 1st layer straight waveguide 4a and a 2nd layer straight waveguide 4a stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 4a401 is connected to the 1+2 layer straight waveguide 3a301;

[0021] The first layer straight waveguide 3c 303, the first layer S-bend waveguide 4c 404 and the first layer straight waveguide 4c 405 are connected in sequence;

[0022] Along the light incident direction, the third-layer straight waveguide 4b 402 is sequentially connected to the third-layer S-bend waveguide 4b 403, the projection area of ​​the third-layer straight waveguide 4b 402 covers the 1+2-layer straight waveguide 4a 401, the end projection area of ​​the third-layer S-bend waveguide 4b 403 does not cover the 1+2-layer straight waveguide 4a 401, and the end projection area of ​​the third-layer S-bend waveguide 4b 403 and the first-layer straight waveguide 4c 405 are respectively located on both sides of the 1+2-layer straight waveguide 4a 401.

[0023] Preferably, the waveguide core layer located in the 3D output area 500 includes a 1+2 layer straight waveguide 5a 501, a 3 layer straight waveguide 5b 502 and a 1 layer straight waveguide 5c 503;

[0024] The 1+2 layer straight waveguide 5a 501 includes a 1st layer straight waveguide 5a and a 2nd layer straight waveguide 5a stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 5a 501 is connected to the 1+2 layer straight waveguide 4a 401;

[0025] The first layer straight waveguide 5c 503 is connected to the first layer straight waveguide 4c 405;

[0026] The third layer straight waveguide 5b 502 is connected to the third layer S-bend waveguide 4b 403, and the projection area of ​​the third layer straight waveguide 5b 502 and the first layer straight waveguide 5c 503 are respectively located on both sides of the 1+2 layer straight waveguide 5a501.

[0027] Preferably, based on the light transmission plane, the first layer waveguide a, the second layer waveguide a, the first layer waveguide c and the third layer waveguide b are parallel to each other.

[0028] Preferably, the refractive index of the composite buried layer 302 is 1.57-4.

[0029] Preferably, the nanoparticles include one or more of metal nanomaterials, carbon nanomaterials and polymer nanomaterials, and the particle size of the nanoparticles is 10-100 nm; the doping amount of the nanoparticles in the composite buried layer 302 is 0.1-5 wt‰.

[0030] The present invention provides a method for preparing the all-optical switch described in the above technical solution, comprising the following steps:

[0031] According to the structure of the waveguide core layer, the waveguide core layer is constructed on the upper surface of the substrate layer 100 by using a photolithography process to obtain a waveguide core layer / substrate device;

[0032] The raw materials for preparing the upper cladding layer 600 are coated on the outside of the waveguide core layer in the waveguide core layer / substrate device, and the upper cladding layer 600 is formed on the outside of the waveguide core layer through thermal curing to obtain the all-optical switch.

[0033] Beneficial effects: The all-optical switch provided by the present invention comprises a substrate layer 100, a waveguide core layer constructed on the upper surface of the substrate layer 100, and an upper cladding layer 600 coated on the outside of the waveguide core layer, wherein the waveguide core layer is an asymmetric Mach-Zehnder interferometer type 1×33D waveguide core layer, and the refractive index of the waveguide core layer is higher than that of the substrate layer 100 and the upper cladding layer 600; along the light incident direction, the waveguide core layer is sequentially divided into an input area 200, a first coupling area 300, a second coupling area 400 and a 3D output area 500; a composite buried layer 302 is arranged inside the waveguide core layer located in the first coupling area 300, and the composite buried layer 302 comprises a polymer matrix and nanoparticles doped in the polymer matrix. The present invention designs the all-optical switch based on the 3D multilayer coupling structure and the photothermal effect of nanoparticles (such as PPy-NPs). The all-optical switch adopts a 1×3MZI type optical waveguide structure, which can realize the output of signal light in the vertical direction. Compared with the planar structure, the 3D optical waveguide structure can add more optical path layers in the vertical direction, and can integrate more photonic devices in a limited chip area, thereby enhancing the anti-interference ability of the photonic system and meeting the requirements of miniaturization and high-density integration of photonic devices. It also has the characteristics of low power consumption, low loss and fast response, and has broad application prospects in the fields of all-optical communication, optical signal processing, photonic integration, etc.

[0034] Furthermore, the present invention prepares the composite buried layer 302 by combining 0-dimensional PPy-NPs with polymer materials, and utilizes the good light absorption characteristics and photothermal conversion efficiency of PPy-NPs in a wide band range. The wide-band characteristics enable the all-optical switch to adapt to the optical communication requirements of different bands, and the good photothermal conversion characteristics can effectively reduce the switching power consumption of the device.

[0035] Furthermore, the present invention adopts a 3D MZI optical waveguide structure in the signal light input area, which can 00 Mode signal light is converted to E 01 mode, while E 00 The mode pump light is still E 00 mode. By separating E 00 Mode pump light and E 01 Mode signal light can effectively reduce the energy loss of signal light. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the structure of the all-optical switch in Example 1;

[0037] Figure 2 is a schematic cross-sectional view of the interference arm of the all-optical switch at the input region in Example 1;

[0038] Figure 3 is a schematic cross-sectional view of the all-optical switch in the first coupling region in Example 1;

[0039] Figure 4 is a schematic cross-sectional view of the all-optical switch in the second coupling region in Example 1;

[0040] Figure 5 is a process flow chart of preparing the all-optical switch in Example 1;

[0041] Figure 6 The 3D asymmetric MZI structure E is a waveguide core layer in the input region. 00 Mode-E 01 Mode light coupling analysis diagram;

[0042] Figure 7 The relationship curve between the waveguide width (waveguide core layer a width) and coupling efficiency of the 3D asymmetric MZI structure with the waveguide core layer a in the input region;

[0043] Figure 8 The relationship between the incident wavelength and coupling efficiency of the 3D asymmetric MZI structure with the waveguide core layer a in the input region;

[0044] Fig. 9 E in the first coupling region 01 Mode-E 00 Mode light coupling analysis diagram;

[0045] Fig.10 E in the second coupling region 01 Mode-E 00 Mode light coupling analysis diagram;

[0046] Fig.11 It is the relationship curve between the waveguide core layer c width and coupling efficiency;

[0047] Fig.12 is a curve diagram showing the relationship between the relative position Δy of the center of the waveguide core layer a and the center of the waveguide core layer c and the coupling efficiency;

[0048] Fig.13 It is the relationship curve between the width of waveguide core layer b and coupling efficiency;

[0049] Fig.14 is a curve diagram showing the relationship between the relative position Δx of the center of waveguide core layer a and the center of waveguide core layer b and the coupling efficiency;

[0050] Fig.15 is a graph showing the relationship between input power consumption and the extinction ratio at the output ports of the waveguide core layer b and the waveguide core layer c;

[0051] In the figure, 100 is the base layer; 600 is the upper cladding layer; 200 is the input area; 300 is the first coupling area; 400 is the second coupling area; 500 is the 3D output area; the waveguide core layer is divided into waveguide core layer a, waveguide core layer b and waveguide core layer c; 201 is the 1+2 layer straight waveguide 1a; 202 is the 1st layer S-bend waveguide 1a; 203 is the 2nd layer S-bend waveguide 1a; 204 is the 1st layer coupled arm waveguide a; 205 is the 2nd layer coupled arm waveguide a; 206 is the 1st layer S-bend waveguide 2a; 207 is the 2 layers of S-bend waveguide 2a; 208 is the 1st+2nd layer of straight waveguide 2a; 301 is the 1st+2nd layer of straight waveguide 3a; 302 is the composite buried layer; 303 is the 1st layer of straight waveguide 3c; 401 is the 1st+2nd layer of straight waveguide 4a; 402 is the 3rd layer of straight waveguide 4b; 403 is the 3rd layer of S-bend waveguide 4b; 404 is the 1st layer of S-bend waveguide 4c; 405 is the 1st layer of straight waveguide 4c; 501 is the 1st+2nd layer of straight waveguide 5a; 502 is the 3rd layer of straight waveguide 5b; 503 is the 1st layer of straight waveguide 5c. DETAILED DESCRIPTION

[0052] The present invention provides an all-optical switch, comprising a substrate layer 100, a waveguide core layer constructed on the upper surface of the substrate layer 100, and an upper cladding layer 600 coated on the outside of the waveguide core layer, wherein the waveguide core layer is an asymmetric Mach-Zehnder interferometer type 1×33D waveguide core layer, and the refractive index of the waveguide core layer is higher than that of the substrate layer 100 and the upper cladding layer 600;

[0053] Along the light incident direction, the waveguide core layer is sequentially divided into an input region 200, a first coupling region 300, a second coupling region 400 and a 3D output region 500;

[0054] A composite buried layer 302 is disposed inside the waveguide core layer located in the first coupling region 300 . The composite buried layer 302 includes a polymer matrix and nanoparticles doped in the polymer matrix. The polymer matrix and the nanoparticles are made of different materials.

[0055] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art or are prepared by methods well known to those skilled in the art.

[0056] In the related art, the 2D planar photonic structure is limited by the physical space. As the complexity of photonic integrated devices increases, how to integrate more functional devices in a limited planar space is an urgent problem to be solved in this field. In addition, the close arrangement of devices easily leads to crosstalk between adjacent devices, which in turn affects the transmission quality of optical signals. The present invention adopts a 3D optical waveguide structure, which can add more optical path layers in the vertical direction, so that multiple functional modules can be superimposed on different planes, and more photonic devices can be integrated in a limited chip area, which can achieve higher integration and functional complexity. In addition, the 3D optical waveguide structure can effectively isolate different signal paths by separating the optical paths at different heights, thereby enhancing the anti-interference ability of the photonic system. The all-optical switch described in the present invention is described in detail below.

[0057] The all-optical switch of the present invention comprises a substrate layer 100, a waveguide core layer constructed on the upper surface of the substrate layer 100, and an upper cladding layer 600 coated on the outside of the waveguide core layer, and the refractive index of the waveguide core layer is higher than that of the substrate layer 100 and the upper cladding layer 600. As an embodiment of the present invention, the refractive index of the substrate layer 100 may be 1.45; the substrate layer 100 may be a silicon-based silica substrate, the silicon-based silica substrate comprises a silicon layer and a silica layer arranged on the upper surface of the silicon layer, and the waveguide core layer is specifically constructed on the upper surface of the silica layer; the thickness (h 100 ) can be 0.5 to 1 mm, specifically 525 μm.

[0058] As an embodiment of the present invention, the refractive index of the upper cladding layer 600 may be 1.49; the raw material for preparing the upper cladding layer 600 may be a polymer material, and the polymer material may include polymethyl methacrylate, polyimide, polyvinyl alcohol or EPO Clad; the thickness (h 600 ) can be 0.5 to 20 μm, and specifically can be 10 μm.

[0059] The waveguide core layer of the present invention is an asymmetric Mach-Zehnder interferometer (MZI) type 1×33D waveguide core layer; as an embodiment of the present invention, the refractive index of the waveguide core layer can be 1.57. The composition of the waveguide core layer of the present invention is described in detail below.

[0060] In the present invention, along the light incident direction, the waveguide core layer is sequentially divided into an input area 200, a first coupling area 300, a second coupling area 400 and a 3D output area 500; a composite buried layer 302 is arranged inside the waveguide core layer located in the first coupling area 300, and the composite buried layer 302 includes a polymer matrix and nanoparticles doped in the polymer matrix.

[0061] As an embodiment of the present invention, the thickness (h 302 ) can be 0.2 to 2 μm, and the width (w 302 ) can be 1 to 10 μm. As an embodiment of the present invention, the refractive index of the composite buried layer 302 can be 1.57 to 4; the material of the polymer matrix can include SU-8, polymethyl methacrylate or polyimide, and such polymers have good optical transparency and dopability; the nanoparticles can include one or more of metal nanomaterials, carbon nanomaterials and polymer nanomaterials, the metal nanomaterials can be gold nanoparticles or silver nanoparticles, the carbon nanomaterials can be graphene, the polymer nanomaterials can be conjugated polymer nanomaterials, and the conjugated polymer nanomaterials can specifically be polypyrrole nanoparticles (PPy-NPs); the particle size of the nanoparticles can be 10 to 100 nm; the doping amount of the nanoparticles in the composite buried layer 302 can be 0.1 to 5 wt‰, specifically 0.1 wt‰, 0.5 wt‰, 1 wt‰, 2 wt‰, 3 wt‰, 4 wt‰ or 5 wt‰.

[0062] The nanoparticles used in the embodiment of the present invention are PPy-NPs, which have good light absorption characteristics. Compared with traditional optical switch materials (such as gold electrodes), PPy-NPs can achieve significant light-to-heat conversion effects under lower light excitation, which is beneficial to reduce the switching power consumption of the device. In addition, PPy-NPs can effectively absorb light energy in a wide wavelength range. This wide spectrum absorption ability makes PPy-NPs not only suitable for conventional optical communication bands, but also can be used in emerging multi-wavelength optical communication systems, improving its adaptability and performance in complex light environments. In an embodiment of the present invention, taking the nanoparticles as PPy-NPs as an example, the refractive index of the composite buried layer 302 can be regulated by adjusting the particle size and doping amount of PPy-NPs. The composite buried layer 302 is used for signal light phase modulation in the optical waveguide. When the signal light passes through the composite buried layer 302, PPy-NPs can absorb light energy and convert it into heat energy, thereby changing the refractive index and light phase inside the optical waveguide to achieve modulation of the optical signal. In the embodiment of the present invention, an all-optical switch is developed and designed based on the advantages of 3D structure and PPy-NPs, which has the characteristics of high integration and functional complexity, strong anti-interference ability, low power consumption and fast response, and has important research significance and broad application prospects.

[0063] As an embodiment of the present invention, the material of the waveguide core layer may be a polymer photoresist, and the polymer photoresist may specifically include SU-8, NR9-1500PY, ZEP 520A or EPO Core; polymer photoresist can achieve high resolution and fine pattern production in ultraviolet lithography, ensure smooth edges of the optical waveguide, and reduce scattering losses in optical signal transmission.

[0064] The waveguide core layer of the present invention is described in detail below.

[0065] As an embodiment of the present invention, based on the upper surface of the base layer 100, the waveguide core layer is sequentially provided with a first waveguide layer, a second waveguide layer and a third waveguide layer from bottom to top, the first waveguide layer includes a first waveguide layer a and a first waveguide layer c, the second waveguide layer includes a second waveguide layer a, and the third waveguide layer includes a third waveguide layer b. Figure 1 As shown, in the embodiment of the present invention, the waveguide core layer as a whole includes waveguide core layer a, waveguide core layer b and waveguide core layer c, wherein waveguide core layer a is a two-layer structure, and is respectively located in the first waveguide layer and the second waveguide layer, that is, the waveguide core layer a includes the first waveguide layer a and the second waveguide layer a; the waveguide core layer b is a single-layer structure, and is located in the third waveguide layer, that is, the waveguide core layer b is the third waveguide layer b; the waveguide core layer c is a single-layer structure, and is located in the first waveguide layer, that is, the waveguide core layer c is the first waveguide layer c. Compared with the planar structure, in the waveguide core layer described in the embodiment of the present invention, the waveguide core layer b and the waveguide core layer c can realize the output of signal light at different positions in the vertical direction, so the 3D waveguide structure allows optical signals to be transmitted in multiple dimensions, improves the utilization of space, and effectively increases the bandwidth and capacity of the system. In addition, the 3D waveguide structure separates different signal channels at different height layers, which can effectively reduce crosstalk between waveguides and reduce signal distortion and the introduction of noise.

[0066] As an embodiment of the present invention, based on the light transmission plane, the first waveguide a, the second waveguide a, the first waveguide c and the third waveguide b are parallel to each other. The distribution of the first waveguide a, the second waveguide a, the third waveguide b and the first waveguide c is described in detail below.

[0067] As an embodiment of the present invention, the first waveguide a and the second waveguide a are both located in the input area 200, the first coupling area 300, the second coupling area 400 and the 3D output area 500, and the first waveguide a and the second waveguide a located in the input area 200 have a 3D asymmetric Mach-Zehnder interferometer structure, the composite buried layer 302 is arranged between the first waveguide a and the second waveguide a located in the first coupling area 300, and the first waveguide a and the second waveguide a located in the second coupling area 400 and the 3D output area 500 are stacked.

[0068] As an embodiment of the present invention, the third layer waveguide b is located in the second coupling region 400 and the 3D output region 500, and the third layer waveguide b does not contact the second layer waveguide a. Along the light incident direction, the projection area of ​​the starting end of the third layer waveguide b located in the second coupling region 400 covers the second layer waveguide a below, and the projection area of ​​the third layer waveguide b located in the 3D output region 500 does not cover the second layer waveguide a. As an embodiment of the present invention, an interlayer is provided between the starting end of the third layer waveguide b and the second layer waveguide a thereunder, and the material of the interlayer may include a polymer material; specifically, the material of the interlayer is the same as the material of the upper cladding layer 600.

[0069] As an embodiment of the present invention, the first layer waveguide c is located in the first coupling area 300, the second coupling area 400 and the 3D output area 500, and the first layer waveguide c is not in contact with the first layer waveguide a, and the projection area of ​​the third layer waveguide b located in the 3D output area 500 and the first layer waveguide c are respectively located on both sides of the first layer waveguide a.

[0070] The specific structures of the waveguide core layers located in the input region 200 , the first coupling region 300 , the second coupling region 400 and the 3D output region 500 are described in detail below.

[0071] As an embodiment of the present invention, the waveguide core layer located in the input area 200 includes a 1+2 layer straight waveguide 1a201, a 1st layer S-bend waveguide 1a202, a 2nd layer S-bend waveguide 1a203, a 1st layer coupled arm waveguide a204, a 2nd layer coupled arm waveguide a205, a 1st layer S-bend waveguide 2a206, a 2nd layer S-bend waveguide 2a207 and a 1+2 layer straight waveguide 2a208; the 1+2 layer straight waveguide 1a201 includes a 1st layer straight waveguide 1a and a 2nd layer straight waveguide 1a stacked sequentially from bottom to top, and the 1+2 layer straight waveguide 2a208 includes a 1st layer straight waveguide 2a and a 2nd layer straight waveguide 2a stacked sequentially from bottom to top; the 1st layer straight waveguide 1a, the 1st layer S-bend waveguide 1a202, the 1st layer coupled arm waveguide a204, the 2nd layer coupled arm waveguide a205, the 1st layer S-bend waveguide 2a206, the 2nd layer S-bend waveguide 2a207 and the 1+2 layer straight waveguide 2a208 204, the first layer S-bend waveguide 2a 206 are connected to the first layer straight waveguide 2a in sequence; the second layer straight waveguide 1a, the second layer S-bend waveguide 1a 203, the second layer coupled arm waveguide a205, the second layer S-bend waveguide 2a 207 are connected to the second layer straight waveguide 2a in sequence.

[0072] As an embodiment of the present invention, the waveguide core layer located in the first coupling region 300 includes a 1+2 layer straight waveguide 3a 301 and a 1 layer straight waveguide 3c 303; the 1+2 layer straight waveguide 3a 301 includes a 1 layer straight waveguide 3a, a composite buried layer 302 and a 2 layer straight waveguide 3a stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 3a 301 is connected to the 1+2 layer output straight waveguide 2a 208.

[0073] As an embodiment of the present invention, the waveguide core layer located in the second coupling region 400 includes a 1+2 layer straight waveguide 4a 401, a 3 layer straight waveguide 4b 402, a 3 layer S-bend waveguide 4b 403, a 1 layer S-bend waveguide 4c 404 and a 1 layer straight waveguide 4c 405; the 1+2 layer straight waveguide 4a 401 includes a 1 layer straight waveguide 4a and a 2 layer straight waveguide 4a stacked sequentially from bottom to top; and the 1+2 layer straight waveguide 4a 401 is connected to the 1+2 layer straight waveguide 3a 301; the 1 layer straight waveguide 3c 303, the 1 layer S-bend waveguide 4c 404 and the 1 layer straight waveguide 4c 405 are sequentially connected; along the light incident direction, the 3 layer straight waveguide 4b 402 is connected to the 3 layer S-bend waveguide 4b 403 are connected in sequence, the projection area of ​​the third layer straight waveguide 4b 402 covers the 1+2 layer straight waveguide 4a401, the end projection area of ​​the third layer S-bend waveguide 4b 403 does not cover the 1+2 layer straight waveguide 4a401, and the end projection area of ​​the third layer S-bend waveguide 4b 403 and the first layer straight waveguide 4c 405 are respectively located on both sides of the 1+2 layer straight waveguide 4a401.

[0074] As an embodiment of the present invention, the waveguide core layer located in the 3D output area 500 includes a 1+2-layer straight waveguide 5a501, a 3-layer straight waveguide 5b502 and a 1-layer straight waveguide 5c503; the 1+2-layer straight waveguide 5a501 includes a 1-layer straight waveguide 5a and a 2-layer straight waveguide 5a stacked in sequence from bottom to top; and the 1+2-layer straight waveguide 5a501 is connected to the 1+2-layer straight waveguide 4a401; the 1-layer straight waveguide 5c503 is connected to the 1-layer straight waveguide 4c405; the 3-layer straight waveguide 5b502 is connected to the 3-layer S-bend waveguide 4b403, and the projection area of ​​the 3-layer straight waveguide 5b502 and the 1-layer straight waveguide 5c503 are respectively located on both sides of the 1+2-layer straight waveguide 5a501.

[0075] The structures of the first layer waveguide a, the second layer waveguide a, the third layer waveguide b and the first layer waveguide c are described in detail below.

[0076] As an embodiment of the present invention, the first layer waveguide a includes a first layer straight waveguide 1a, a first layer S-bend waveguide 1a 202, a first layer coupled arm waveguide a204, a first layer S-bend waveguide 2a 206, a first layer straight waveguide 2a, a first layer straight waveguide 3a, a first layer straight waveguide 4a and a first layer straight waveguide 5a connected in sequence.

[0077] As an embodiment of the present invention, the second layer waveguide a includes a second layer straight waveguide 1a, a second layer S-bend waveguide 1a 203, a second layer coupled arm waveguide a205, a second layer S-bend waveguide 2a 207, a second layer straight waveguide 2a, a second layer straight waveguide 3a, a second layer straight waveguide 4a and a second layer straight waveguide 5a connected in sequence.

[0078] As an embodiment of the present invention, the first layer waveguide c includes a first layer straight waveguide 3c 303, a first layer S-bend waveguide 4c 404, a first layer straight waveguide 4c 405 and a first layer straight waveguide 5c 503 connected in sequence.

[0079] As an embodiment of the present invention, the third layer waveguide b includes a third layer straight waveguide 4b 402, a third layer S-bend waveguide 4b 403 and a third layer straight waveguide 5b 502 which are connected in sequence.

[0080] The following describes the dimensions of the waveguide core layer located in the input region 200, the first coupling region 300, the second coupling region 400, and the 3D output region 500. As an embodiment of the present invention, the width (w 200 ), the width of the waveguide core layer located in the first coupling region 300 (w 300), the width of the waveguide core layer located in the second coupling region 400 (w 400 ) and the width (w 500 ) is independently 1 to 10 μm; the height of the waveguide core layer located in the input region 200 (h 200 ), the height of the waveguide core layer located in the first coupling region 300 (h 300 ), the height of the waveguide core layer located in the second coupling region 400 (h 400 ) and the height (h 500 ) are independently 1 to 20 μm.

[0081] As an embodiment of the present invention, the heights of the first waveguide a, the second waveguide a, the third waveguide b and the first waveguide c are independently 1-10 μm and the widths are independently 1-10 μm. The heights and widths of the structures are described in detail below.

[0082] As an embodiment of the present invention, with respect to the first layer waveguide a and the second layer waveguide a, the width (w 201 ), the width (w 202 ), the width of the second layer S-bend waveguide 1a 203 (w 203 ), the width of the first layer coupling arm waveguide a 204 (w 204 ), the width of the second layer coupling arm waveguide a 205 (w 205 ), the width of the first layer S-bend waveguide 2a206 (w 206 ), the width (w 207 ) and the width (w 208 ), the width of the 1+2 layer straight waveguide 3a 301 (w 301 ), the width of the 1+2 layer straight waveguide 4a401 (w 401 ) and the width (w 501 ) is independently 1 to 10 μm, specifically 5.14 μm; the height (h 202 ), the height of the second layer S-bend waveguide 1a 203 (h 203 ), the height of the first layer coupling arm waveguide a 204 (h 204 ), the height of the second layer coupling arm waveguide a 205 (h 205 ), the height of the first layer S-bend waveguide 2a 206 (h 206 ) and the height (h 207) is independently 1 to 10 μm, specifically 5 μm; the height (h 201 ), the height of the 1+2 layer straight waveguide 2a 208 (h 208 ), the height of the 1+2 layer straight waveguide 3a 301 (h 301 ), the height of the 1+2 layer straight waveguide 4a401 (h 401 ) and the height (h 501 ) is independently 2 to 20 μm, specifically 10 μm. As an embodiment of the present invention, the width of the first waveguide a at any position is the same as that of the second waveguide a at any position, and the height of the first waveguide a at any position is the same as that of the second waveguide a at any position.

[0083] As an embodiment of the present invention, with respect to the third layer waveguide b, the width (w 402 ), the width (w 403 ) and the width (w 502 ) is independently 1 to 9 μm, specifically 4.45 μm; the height (h 402 ), the height of the third layer S-bend waveguide 4b 403 (h 403 ) and the height (h 502 ) are independently 1-10 μm, specifically 5 μm. As an embodiment of the present invention, the width of the third layer waveguide b at any position is the same, and the height of the third layer waveguide b at any position is the same.

[0084] As an embodiment of the present invention, with respect to the first layer waveguide c, the width (w 303 ), the width (w 404 ), the width of the first straight waveguide 4c 405 (w 405 ) and the width (w 503 ) is independently 1 to 9 μm, specifically 4.46 μm; the height (h 303 ), the height of the first layer S-bend waveguide 4c 404 (h 404 ), the height of the first straight waveguide 4c 405 (h 405 ) and the height (h 503) are independently 1-10 μm, specifically 5 μm. As an embodiment of the present invention, the width of the first layer waveguide c at any position is the same, and the height of the first layer waveguide c at any position is the same.

[0085] The length and spacing of each structure are described in detail below.

[0086] As an embodiment of the present invention, the length (l 21 ) is 1 to 1.5 cm, specifically 1 cm; the length of the first layer of coupled arm waveguide a 204 is the same as the length of the second layer of coupled arm waveguide a 205 (both are represented by l 23 ), which can be 0.2-1 cm, specifically 0.5 cm; the length of the 1+2 layer straight waveguide 2a 208 (l 25 ) is 0.2-0.8 cm, and specifically can be 0.3 cm. As an embodiment of the present invention, along the light transmission direction, the length of the first layer S-bend waveguide 1a202 is the same as the length of the second layer S-bend waveguide 1a203 (both are represented by l 22 ), which can be 0.1-1 cm, specifically 0.2 cm; the length of the first layer S-bend waveguide 2a 206 is the same as the length of the second layer S-bend waveguide 2a 207 (both are represented by l 24 ), which can be 0.1-1 cm, and specifically 0.2 cm. As an embodiment of the present invention, along the light incident direction, the horizontal distance (d 21 ) is 1 to 20 μm, specifically 10 μm; the horizontal distance (d ) between the end of the second layer S-bend waveguide 1a 203 and the starting end of the second layer coupling arm waveguide a 205 and the first + second layer straight waveguide 1a 201 22 ) is 3 to 50 μm, specifically 21 μm; the horizontal distance (d ) between the end of the first layer of coupled arm waveguide a 204 and the starting end of the first layer of S-bend waveguide 2a 206 and the first + second layer of straight waveguide 1a201 23 ) is 1 to 20 μm, specifically 10 μm; the horizontal distance (d ) between the end of the second layer coupling arm waveguide a205 and the starting end of the second layer S-bend waveguide 2a 207 and the first + second layer straight waveguide 1a 201 24 ) is 3 to 50 μm, and can be specifically 21 μm.

[0087] In the embodiment of the present invention, a 3D asymmetric MZI structure is used to realize the signal light from E 00 Mode to E 01Mode conversion, wherein the conversion process depends on the size of the first layer S-bend waveguide 1a202, the second layer S-bend waveguide 1a203, the first layer S-bend waveguide 2a206 and the second layer S-bend waveguide 2a207 for control. Specifically, the first layer S-bend waveguide 1a202 and the first layer S-bend waveguide 2a206 have the same size; the second layer S-bend waveguide 1a203 and the second layer S-bend waveguide 2a207 have the same size.

[0088] In the embodiment of the present invention, 00 The input wavelength of the mode signal light is 1.4~1.6μm, E 00 The mode pump light excitation wavelength is 0.35~1.4μm. After passing through the input area 200, E 00 Mode signal light is converted to E 01 Mode, E 00 The mode pump light is still E 00 mode; by separating the pump light E 00 Mode and signal light E 01 mode, which can effectively reduce the energy loss of signal light and improve the photothermal conversion efficiency of pump light.

[0089] As an embodiment of the present invention, the length of the 1+2 layer straight waveguide 3a 301 is the same as the length of the 1 layer straight waveguide 3c 303 (both are represented by 1 31 ), which can be 0.2-1 cm, specifically 0.5 cm; the distance between the 1+2 layer straight waveguide 3a301 and the 1 layer straight waveguide 3c 303 is the coupling spacing (d 31 ), the coupling spacing is 0.1-2 μm, and can be specifically 0.5 μm.

[0090] As an embodiment of the present invention, the length (l 41 ) is 0.2 to 1 cm, specifically 0.5 cm; the length of the 1+2 layer straight waveguide 4a401 (symbolized as l 41 +l 42 ) is 0.25 to 1.4 cm, specifically 0.65 cm; the length of the third layer straight waveguide 4b 402 (l 41 ) is 0.2 to 1 cm, specifically 0.5 cm; along the light transmission direction, the length of the third layer S-bend waveguide 4b 403 (l 42 ) is 0.05-0.4 cm, specifically 0.15 cm; along the light transmission direction, the length (l 43 ) is 0.05-0.4 cm, specifically 0.15 cm; the vertical distance (d41 ) is 0.1-2 μm, specifically 0.5 μm; the horizontal distance (d 42 ) is 5 to 30 μm, specifically 15 μm; the horizontal distance (d 43 ) is 5 to 30 μm, and can be specifically 15 μm.

[0091] In the embodiment of the present invention, the first layer S-bend waveguide 1a 202, the second layer S-bend waveguide 1a 203, the first layer S-bend waveguide 2a 206, the second layer S-bend waveguide 2a 207, the third layer S-bend waveguide 4b 403 and the first layer S-bend waveguide 4c 404 are curved waveguides, and the curved waveguides have a waveguide shape according to a cosine function, and a mathematical expression thereof is: x=(1-cosπz / l)·d, wherein z represents a coordinate position along a waveguide light transmission direction, x represents a horizontal coordinate position perpendicular to a waveguide transmission plane, l represents a length of the curved waveguide in the z direction, and d represents a displacement of the curved waveguide in the x direction.

[0092] As an embodiment of the present invention, the length (l 51 ), the length of the third layer straight waveguide 5b502 (l 52 ) and the length (l 53 ) is independently 1 to 1.5 cm, and can be specifically 1 cm.

[0093] The all-optical switch provided by the present invention comprises an input region, a coupling region and a 3D output region. The key part of the input region is an asymmetric MZI waveguide structure, which functions to couple E 00 Mode signal light is converted to E 01 The coupling region includes a low-layer coupling waveguide, a high-layer coupling waveguide, and an E 01 Mode transmission waveguides and nanoparticles (such as PPy-NPs), among which 0-dimensional PPy-NPs (0D PPy-NPs) have efficient photothermal conversion characteristics in a wide spectrum range, and the waveguide mode can be regulated by the photothermal effect. 01 Mode signal light is converted to E 00 The 3D output area includes two E 00 mode output waveguide and an E 01 The mode output waveguide is different from the traditional planar optical switch and can realize the output of signal light at different positions in the vertical direction. The all-optical switch provided by the present invention has a compact structure, is easy to integrate, has low switch power consumption, and has a short response time. It has broad application prospects in the fields of all-optical communication, optical signal processing, photon integration, etc.

[0094] The present invention provides a method for preparing the all-optical switch described in the above technical solution, comprising the following steps:

[0095] According to the structure of the waveguide core layer, the waveguide core layer is constructed on the upper surface of the substrate layer 100 by using a photolithography process to obtain a waveguide core layer / substrate device;

[0096] The raw materials for preparing the upper cladding layer 600 are coated on the outside of the waveguide core layer in the waveguide core layer / substrate device, and the upper cladding layer 600 is formed on the outside of the waveguide core layer through thermal curing to obtain the all-optical switch.

[0097] Combine the following Figure 5 The preparation method of the all-optical switch of the present invention is described in detail.

[0098] As an embodiment of the present invention, the base layer 100 can be specifically a silicon-based silica substrate, which is preferably surface cleaned before use. Specifically, the silicon-based silica substrate is immersed in acetone, ultrasonically cleaned for 15 to 20 minutes, and then the surface of the substrate is wiped 3 to 5 times with acetone cotton balls and ethanol cotton balls respectively, and then rinsed with deionized water for 3 to 5 times, and finally placed in an oven and baked at 100 to 120°C for 1 to 2 hours to obtain a clean substrate.

[0099] After obtaining the clean substrate, the present invention constructs the waveguide core layer on the upper surface of the base layer 100 (i.e., the surface of the silicon dioxide layer of the clean substrate) using a photolithography process according to the structure of the waveguide core layer to obtain a waveguide core layer / base device. As an embodiment of the present invention, the first waveguide layer, the composite buried layer 302, the second waveguide layer, the interlayer and the third waveguide layer are sequentially prepared on the surface of the silicon dioxide layer of the clean substrate, which are described in detail below.

[0100] As an embodiment of the present invention, the preparation method of the first layer of waveguide includes sequentially performing spin coating, pre-baking, photolithography, post-baking and development. In the embodiment of the present invention, the polymer photoresist is dripped onto the surface of the silicon dioxide layer of the clean substrate for spin coating, and the spin coating includes sequentially performing the first spin coating and the second spin coating, and the rotation speed of the second spin coating is higher than the rotation speed of the first spin coating; the rotation speed of the first spin coating is 1000-2000r / min, specifically 1500r / min, and the duration is 10-30s, specifically 15s; the rotation speed of the second spin coating is 2000-4000r / min, specifically 3000r / min, and the duration is 50-80s, specifically 50s. The pre-baking described in the embodiment of the present invention includes sequentially performing a first pre-baking and a second pre-baking, wherein the temperature of the second pre-baking is higher than that of the first pre-baking; the temperature of the first pre-baking is 60-90°C, specifically 60°C, and the holding time is 10-20min, specifically 15min; the temperature of the second pre-baking is 90-110°C, specifically 90°C, and the holding time is 30-40min, specifically 30min; after the holding time is completed, it is naturally cooled to room temperature. In the embodiment of the present invention, the substrate after pre-baking is specifically subjected to ultraviolet exposure to realize the photolithography; wherein the wavelength of the ultraviolet light used is 360-370nm, and the intensity of the ultraviolet light is 20-200mW / cm 2 , the exposure time is 5 to 20 seconds, specifically 10 seconds. The post-baking described in the embodiment of the present invention includes sequentially performing a first post-baking and a second post-baking, the temperature of the second post-baking is higher than the temperature of the first post-baking; the temperature of the first post-baking is 60 to 90°C, specifically 60°C, and the insulation time is 10 to 20 minutes, specifically 15 minutes; the temperature of the second post-baking is 90 to 110°C, specifically 95°C, and the insulation time is 30 to 40 minutes, specifically 30 minutes; after the insulation is completed, it is naturally cooled to room temperature. In the embodiment of the present invention, the substrate after photolithography is immersed in a developer for the development, and the development time can be 10 to 40 seconds, specifically 15 seconds; the polymer photoresist in the area not irradiated by ultraviolet rays can be removed by the development, and finally the first layer of waveguide is formed on the upper surface of the base layer 100 to obtain the first device.

[0101] As an embodiment of the present invention, the preparation method of the composite buried layer 302 includes sequentially performing spin coating, pre-baking, photolithography, post-baking and development. In the embodiment of the present invention, the nanoparticles are mixed with a polymer material solution, and the obtained mixed material is dripped onto the upper surface of the first device for spin coating; the present invention has no special restrictions on the concentration of the polymer material solution and the solvent used, as long as the composite buried layer 302 that meets the requirements is obtained; in the embodiment of the present invention, the model of the polymer material solution used is specifically SU-82005. As an embodiment of the present invention, the dosage ratio of the nanoparticles to the polymer material solution can be 0.1-1.5g:50-100mL, specifically 0.12g:100mL; the mixing includes stirring and ultrasonicating in sequence, the mixing temperature is 20-40°C, specifically 30°C, the stirring time can be 6-12h, and the ultrasonicating time can be 16-24h; the spin coating includes performing a first spin coating and a second spin coating in sequence, and the rotation speed of the second spin coating is higher than the rotation speed of the first spin coating; the rotation speed of the first spin coating is 3000-5000r / min, specifically 3000r / min, and the duration is 10-30s, specifically 15s; the rotation speed of the second spin coating is 6000-8000r / min, specifically 7000r / min, and the duration is 50-100s, specifically 80s. The pre-baking described in the embodiment of the present invention includes sequentially performing a first pre-baking and a second pre-baking, wherein the temperature of the second pre-baking is higher than that of the first pre-baking; the temperature of the first pre-baking is 60-90°C, specifically 60°C, and the holding time is 10-20min, specifically 15min; the temperature of the second pre-baking is 90-110°C, specifically 90°C, and the holding time is 30-40min, specifically 30min; after the holding time is completed, it is naturally cooled to room temperature. In the embodiment of the present invention, the substrate after pre-baking is specifically subjected to ultraviolet exposure to realize the photolithography; wherein the wavelength of the ultraviolet light used is 360-370nm, and the intensity of the ultraviolet light is 20-200mW / cm 2, the exposure time is 2 to 10 seconds, specifically 5 seconds. The post-baking in the embodiment of the present invention includes sequentially performing a first post-baking and a second post-baking, the temperature of the second post-baking is higher than the temperature of the first post-baking; the temperature of the first post-baking is 60 to 90°C, specifically 60°C, and the holding time is 10 to 20 minutes, specifically 15 minutes; the temperature of the second post-baking is 90 to 120°C, specifically 90°C, and the holding time is 30 to 40 minutes, specifically 30 minutes; after the holding is completed, it is naturally cooled to room temperature. In the embodiment of the present invention, the substrate after photolithography is immersed in a developer for the development, and the development time can be 5 to 20 seconds, specifically 10 seconds; through the development, a composite buried layer 200 is formed on a part of the upper surface of the first layer of waveguide in the first device (specifically the upper surface of the first layer of straight waveguide 3a), and a second device is obtained.

[0102] As an embodiment of the present invention, the preparation method of the second waveguide refers to the preparation method of the first waveguide, which will not be repeated here, and finally a third device (including the base layer 100, the first waveguide, the composite buried layer 200 and the second waveguide) is obtained.

[0103] As an embodiment of the present invention, the preparation method of the interlayer includes sequentially performing spin coating and thermal curing treatment. In the embodiment of the present invention, the polymer material is specifically added to the partial upper surface of the third device (corresponding to the area where the interlayer is located) for spin coating; the spin coating includes sequentially performing the first spin coating and the second spin coating, and the rotation speed of the second spin coating is higher than the rotation speed of the first spin coating; the rotation speed of the first spin coating is 3000-5000r / min, specifically 3000r / min, and the duration is 10-30s, specifically 10s; the rotation speed of the second spin coating is 5000-8000r / min, specifically 5000r / min, and the duration is 50-90s, specifically 90s. The temperature of the thermal curing treatment in the embodiment of the present invention is 90-150℃, specifically 120℃; the heat preservation time is 20-90min, specifically 40min, to ensure that the interlayer is completely cured as a benchmark, and obtain the fourth device (including the base layer 100, the first waveguide layer, the composite buried layer 200, the second waveguide layer and the interlayer).

[0104] As an embodiment of the present invention, the preparation method of the third layer of waveguide is operated with reference to the preparation method of the first layer of waveguide, which will not be repeated here, and finally a fifth device (including a substrate layer 100, a first layer of waveguide, a composite buried layer 200, a second layer of waveguide, an interlayer and a third layer of waveguide), i.e., a waveguide core layer / substrate device, is obtained.

[0105] After obtaining the waveguide core layer / substrate device, the present invention coats the preparation material of the upper cladding layer 600 on the outside of the waveguide core layer in the waveguide core layer / substrate device, and forms the upper cladding layer 600 on the outside of the waveguide core layer through thermal curing treatment to obtain the all-optical switch. As an embodiment of the present invention, the coating can be spin coating; the spin coating includes sequentially performing a first spin coating and a second spin coating, and the rotation speed of the second spin coating is higher than the rotation speed of the first spin coating; the rotation speed of the first spin coating is 1000-2000r / min, specifically 1000r / min, and the duration is 10-30s, specifically 10s; the rotation speed of the second spin coating is 2000-3000r / min, specifically 3000r / min, and the duration is 20-30s, specifically 30s. As an embodiment of the present invention, the temperature of the thermal curing treatment is 90-150°C, specifically 120°C; the holding time is 20-90min, specifically 40min, to ensure that the upper cladding layer 600 is completely cured as a benchmark, and the all-optical switch (including the base layer 100, the first waveguide layer, the composite buried layer 200, the second waveguide layer, the interlayer, the third waveguide layer and the upper cladding layer 600) is obtained.

[0106] The all-optical switch provided by the present invention adopts a unique (3+0)D photon integrated structure. By introducing nanoparticles (such as 0D PPy-NPs) on the basis of the 3D structure, the 1×3 all-optical switch device can realize the effective distribution and switching of optical signals between different channels, thereby increasing the integration of the device. In the present invention, a PPy-NPs / polymer composite material is used to prepare a composite buried layer, which has good light absorption characteristics in a wide wavelength range, is conducive to reducing the power consumption of the all-optical switch, and has broad application prospects in multi-wavelength optical communication systems. In addition, the present invention combines traditional spin coating and photolithography processes, so that the preparation method of the all-optical switch is simple and compatible with CMOS processes; high-precision alignment technology is used in the process to ensure the excellent performance of the device, and the use of polymer materials reduces the production cost, which is suitable for large-scale production.

[0107] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0108] Example 1

[0109] like Figure 1 to Figure 4 As shown, the structure of the (3+0)D photon integrated PPy-NPs / polymer 1×3 all-optical switch in this embodiment is as follows:

[0110] From bottom to top, there are a base layer 100, a waveguide core layer and an upper cladding layer 600, wherein the waveguide core layer is an asymmetric Mach-Zehnder interferometer (MZI) type 1×33D waveguide core layer, and the refractive index of the waveguide core layer is higher than that of the base layer 100 and the upper cladding layer 600; the waveguide core layer includes a waveguide core layer a, a waveguide core layer b and a waveguide core layer c, wherein the waveguide core layer a inputs signal light and pump light, and the waveguide core layer b and the waveguide core layer c output signal light; the first waveguide layer includes a first waveguide layer a and a first waveguide layer c, the second waveguide layer includes a second waveguide layer a, and the third waveguide layer includes a third waveguide layer b; with the light transmission plane as a reference, the first waveguide layer a, the second waveguide layer a, the first waveguide layer c and the third waveguide layer b are parallel to each other;

[0111] From the light input to the light output direction, the waveguide core layer is divided into an input region 200, a first coupling region 300, a second coupling region 400 and a 3D output region 500. A composite buried layer 302 is arranged inside the waveguide core layer located in the first coupling region 300. The composite buried layer 302 includes a polymer matrix and nanoparticles doped in the polymer matrix.

[0112] The waveguide core layer located in the input area 200 has a 3D asymmetric MZI structure, including a 1+2 layer straight waveguide 1a 201, a 1st layer S-bend waveguide 1a 202, a 2nd layer S-bend waveguide 1a 203, a 1st layer coupled arm waveguide a 204, a 2nd layer coupled arm waveguide a 205, a 1st layer S-bend waveguide 2a 206, a 2nd layer S-bend waveguide 2a 207 and a 1+2 layer straight waveguide 2a 208; the 1+2 layer straight waveguide 1a 201 includes a 1st layer straight waveguide 1a and a 2nd layer straight waveguide 1a stacked sequentially from bottom to top, the 1+2 layer straight waveguide 2a 208 includes a 1st layer straight waveguide 2a and a 2nd layer straight waveguide 2a stacked sequentially from bottom to top; the 1st layer straight waveguide 1a, the 1st layer S-bend waveguide 1a 202, the first layer of coupled arm waveguide a 204, the first layer of S-bend waveguide 2a 206 are connected in sequence to the first layer of straight waveguide 2a; the second layer of straight waveguide 1a, the second layer of S-bend waveguide 1a 203, the second layer of coupled arm waveguide a 205, the second layer of S-bend waveguide 2a 207 are connected in sequence to the second layer of straight waveguide 2a;

[0113] The waveguide core layer located in the first coupling region 300 includes a 1+2 layer straight waveguide 3a 301 and a 1 layer straight waveguide 3c 303; the 1+2 layer straight waveguide 3a 301 includes a 1 layer straight waveguide 3a, a composite buried layer 302 and a 2 layer straight waveguide 3a stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 3a 301 is connected to the 1+2 layer output straight waveguide 2a 208;

[0114] The waveguide core layer located in the second coupling region 400 includes a 1+2 layer straight waveguide 4a 401, a 3 layer straight waveguide 4b 402, a 3 layer S-bend waveguide 4b 403, a 1 layer S-bend waveguide 4c 404 and a 1 layer straight waveguide 4c 405; the 1+2 layer straight waveguide 4a 401 includes a 1 layer straight waveguide 4a and a 2 layer straight waveguide 4a stacked sequentially from bottom to top; and the 1+2 layer straight waveguide 4a 401 is connected to the 1+2 layer straight waveguide 3a 301; the 1 layer straight waveguide 3c 303, the 1 layer S-bend waveguide 4c 404 and the 1 layer straight waveguide 4c 405 are sequentially connected; along the light incident direction, the 3 layer straight waveguide 4b 402 and the 3 layer S-bend waveguide 4b 403 are connected in sequence, the projection area of ​​the third layer straight waveguide 4b 402 covers the 1+2 layer straight waveguide 4a401, the end projection area of ​​the third layer S-bend waveguide 4b 403 does not cover the 1+2 layer straight waveguide 4a 401, and the end projection area of ​​the third layer S-bend waveguide 4b 403 and the first layer straight waveguide 4c 405 are respectively located on both sides of the 1+2 layer straight waveguide 4a401;

[0115] The waveguide core layer located in the 3D output area 500 includes a 1+2-layer straight waveguide 5a 501, a 3-layer straight waveguide 5b 502 and a 1-layer straight waveguide 5c 503; the 1+2-layer straight waveguide 5a 501 includes a 1-layer straight waveguide 5a and a 2-layer straight waveguide 5a stacked in sequence from bottom to top; and the 1+2-layer straight waveguide 5a 501 is connected to the 1+2-layer straight waveguide 4a 401; the 1-layer straight waveguide 5c 503 is connected to the 1-layer straight waveguide 4c 405; the 3-layer straight waveguide 5b 502 is connected to the 3-layer S-bend waveguide 4b 403, and the projection area of ​​the 3-layer straight waveguide 5b 502 and the 1-layer straight waveguide 5c 503 are respectively located on both sides of the 1+2-layer straight waveguide 5a 501.

[0116] In the all-optical switch of this embodiment, the base layer 100 is a silicon-based silicon dioxide substrate (thickness h 100 525 μm), including a silicon layer and a silicon dioxide layer arranged on the upper surface of the silicon layer, and the waveguide core layer is specifically constructed on the upper surface of the silicon dioxide layer; preparing the upper cladding layer 600 (thickness h 600 The polymer material used is polymethyl methacrylate; the composite buried layer 302 (thickness h 302 0.4 μm) includes a polymer matrix (made of SU-8) and nanoparticles (specifically PPy-NPs, with a particle size of 40 nm) doped in the polymer matrix;

[0117] The polymer photoresist used to prepare the waveguide core layer is SU-8; the dimensions involved in the waveguide core layer are as follows:

[0118] The width of the waveguide core layer a (i.e. w 201 、w 202 、w 203 、w 204 、w 205 、w 206 、w 207 、w 208 、w 301 、w 401 、w 501 ) is 5.14 μm, and the single layer height (h 202 、h 203 、h 204 、h 205 、h 206 、h 207 ) is 5 μm, and the double layer height (h 201 、h 208 、h 301 、h 401 、h 501 ) is 10 μm, the first waveguide core layer a and the second waveguide core layer a have the same thickness and width; the width of the waveguide core layer b (i.e., w 402 、w 403 、w 502 ) is 4.45 μm, and the height (h 402 、h 403 、h 502 ) is 5 μm; the width of the waveguide core layer c (i.e., w 303 、w 404 、w 405 、w 503 ) is 4.46 μm, and the height (h 303 、h 404 、h 405 、h 503 ) is 5 μm;

[0119] The length l of the waveguide core layer located in the input region 200 21 is 1cm, length l 22 is 0.2cm, length l 23 is 0.5cm, length l 24 is 0.2cm; horizontal distance d 21 is 10μm, the horizontal distance d 22 is 21 μm, and the horizontal distance d 23 is 10μm, the horizontal distance d 24The first layer of S-bend waveguide 1a202 is the same size as the first layer of S-bend waveguide 2a 206, and the second layer of S-bend waveguide 1a203 is the same size as the second layer of S-bend waveguide 2a207; the length l of the waveguide core layer located in the first coupling region 300 31 The distance d between the 1st+2nd layer straight waveguide 3a 301 and the 1st layer straight waveguide 3c 303 is 0.5 cm. 31 The length l of the third straight waveguide 4b 402 located in the second coupling region 400 is 0.5 μm; 41 =0.5 cm. Along the light transmission direction, the length l of the third layer S-bend waveguide 4b 403 is 42 is 0.15 cm, and the length l of the first layer S-bend waveguide 4c 404 is 43 0.15 cm; the vertical distance d between the 1st + 2nd layer straight waveguide 4a401 and the 3rd layer straight waveguide 4b 402 41 is 0.5 μm, and the horizontal distance d between the third-layer straight waveguide 4 b 402 and the third-layer straight waveguide 5 b 502 located in the 3D output area 500 is 42 The horizontal distance d between the first straight waveguide 4c 405 and the first straight waveguide 3c 303 located in the first coupling region 300 is 15 μm; 43 The length of the waveguide core layer located in the 3D output region 500 (ie, l 51 , l 52 , l 53 ) is 1cm.

[0120] like Figure 5 As shown, the method for preparing the all-optical switch in this embodiment includes the following steps:

[0121] (1) Preparation of the first waveguide layer

[0122] The silicon-based silica substrate was immersed in acetone and ultrasonically cleaned for 15 minutes, then the surface of the substrate was wiped 4 times with acetone cotton balls and ethanol cotton balls respectively, then rinsed with deionized water 4 times, and finally placed in an oven and baked at 100°C for 2 hours to obtain a clean substrate;

[0123] Add polymer photoresist (SU-8) dropwise onto the surface of the silicon dioxide layer of the clean substrate, and place the substrate in a coating device for spin coating to obtain a spin-coated sample; the spin coating conditions are: pre-coating speed is 1500 r / min, duration is 15 s, then the speed is increased to 3000 r / min, duration is 50 s;

[0124] The spin-coated sample was placed on a hot plate for pre-baking to obtain a pre-baked sample; the pre-baking conditions were: first heating at 60° C. for 15 min, then raising the temperature to 90° C. and heating for 30 min, and after the heating was completed, turning off the hot plate and letting it cool naturally to room temperature;

[0125] The pre-baked sample is placed on a photolithography machine for photolithography. Specifically, the photolithography mask matching the first layer of waveguide is accurately aligned and attached to the surface of the pre-baked sample. Then, the pre-baked sample is exposed to ultraviolet light with a wavelength of 365 nm and an intensity of 40 mW / cm 2 , the exposure time is 10s, and the photolithography sample is obtained;

[0126] The photolithography sample is placed on a hot plate for post-baking to obtain a post-baked sample; the post-baking conditions are: firstly heating at 60° C. for 15 minutes, then raising the temperature to 95° C. and heating for 30 minutes, and after the heating is completed, turning off the hot plate and letting it cool naturally to room temperature;

[0127] The post-baked sample is immersed in a developer for development for 15 seconds to obtain a first device (including a base layer 100 and a first waveguide layer);

[0128] (2) Preparation of composite buried layer 200

[0129] 0.12 g of PPy-NPs powder was added to 100 mL of polymer material solution (specifically, the model may be SU-82005), and stirred for 12 h and ultrasonicated for 24 h at 30° C. to obtain a PPy-NPs / polymer composite material;

[0130] The PPy-NPs / polymer composite material is added dropwise onto the upper surface of the first device, and placed in a coating device for spin coating to obtain a spin-coated sample; the spin coating conditions are: the pre-coating speed is 3000 r / min, the duration is 15 s, and then the speed is increased to 7000 r / min, and the duration is 80 s;

[0131] The spin-coated sample was placed on a hot plate for pre-baking to obtain a pre-baked sample; the pre-baking conditions were: first heating at 60° C. for 15 min, then raising the temperature to 90° C. and heating for 30 min, and after the heating was completed, turning off the hot plate and letting it cool naturally to room temperature;

[0132] The pre-baked sample is placed on a photolithography machine for photolithography. Specifically, the photolithography mask matching the composite buried layer 200 is accurately aligned and attached to the surface of the pre-baked sample. Then, the pre-baked sample is exposed to ultraviolet light with a wavelength of 365 nm and an intensity of 240 mW / cm 2 , the exposure time is 5s, and the photolithography sample is obtained;

[0133] The photolithography sample is placed on a hot plate for post-baking to obtain a post-baked sample; the post-baking conditions are: firstly heating at 60° C. for 15 minutes, then raising the temperature to 90° C. and heating for 30 minutes, and after the heating is completed, turning off the hot plate and letting it cool naturally to room temperature;

[0134] The post-baked sample is immersed in a developer for development for 10 seconds to obtain a second device (including a base layer 100, a first waveguide layer and a composite buried layer 200);

[0135] (3) Preparation of the second waveguide

[0136] Adding polymer photoresist (SU-8) dropwise onto the upper surface of the second device, placing the device in a coating device for spin coating, and obtaining a spin-coated sample; the spin coating conditions are the same as those in step (1);

[0137] Placing the spin-coated sample on a hot plate for pre-baking to obtain a pre-baked sample; the pre-baking conditions are consistent with those in step (1);

[0138] Placing the pre-baked sample on a photolithography machine for photolithography, specifically accurately aligning and attaching a photolithography mask matching the second layer of waveguide to the surface of the pre-baked sample, and then ultraviolet exposure is performed on the pre-baked sample to obtain a photolithography sample; the ultraviolet exposure conditions are consistent with step (1);

[0139] Placing the photolithography sample on a hot plate for post-baking to obtain a post-baked sample; the post-baking conditions are consistent with those in step (1);

[0140] The post-baked sample is immersed in a developer for development to obtain a third device (including a base layer 100, a first waveguide layer, a composite buried layer 200 and a second waveguide layer); the development conditions are consistent with those in step (1);

[0141] (4) Preparation of interlayer

[0142] Add polymethyl methacrylate dropwise onto a portion of the upper surface of the third device (corresponding to the area where the interlayer is located), and place the device in a coating apparatus for spin coating to obtain a spin-coated sample; the spin coating conditions are: the pre-coating speed is 3000 r / min, the duration is 10 s, and then the speed is increased to 5000 r / min, the duration is 90 s;

[0143] The spin-coated sample is placed on a hot plate for heat curing treatment to obtain a fourth device (including a base layer 100, a first waveguide layer, a composite buried layer 200, a second waveguide layer and an interlayer); the heat curing treatment temperature is 120° C., and the heat preservation time is 40 minutes to ensure that the interlayer is completely cured;

[0144] (5) Preparation of the third waveguide

[0145] Adding polymer photoresist (SU-8) dropwise onto the upper surface of the fourth device, placing the device in a coating device for spin coating, and obtaining a spin-coated sample; the spin coating conditions are the same as those in step (1);

[0146] Placing the spin-coated sample on a hot plate for pre-baking to obtain a pre-baked sample; the pre-baking conditions are consistent with those in step (1);

[0147] Placing the pre-baked sample on a photolithography machine for photolithography, specifically accurately aligning and attaching a photolithography mask matching the third layer waveguide to the surface of the pre-baked sample, and then ultraviolet exposure is performed on the pre-baked sample to obtain a photolithography sample; the ultraviolet exposure conditions are consistent with step (1);

[0148] Placing the photolithography sample on a hot plate for post-baking to obtain a post-baked sample; the post-baking conditions are consistent with those in step (1);

[0149] The post-baked sample is immersed in a developer for development to obtain a fifth device (including a base layer 100, a first waveguide layer, a composite buried layer 200, a second waveguide layer and a third waveguide layer); the development conditions are consistent with those in step (1);

[0150] (6) Preparation of upper cladding layer 600

[0151] Add polymethyl methacrylate dropwise onto the upper surface of the fifth device, and place the device in a coating device for spin coating to obtain a spin-coated sample; the spin coating conditions are: pre-coating speed is 1000 r / min, duration is 10 s, then the speed is increased to 3000 r / min, duration is 30 s;

[0152] The spin-coated sample was placed on a hot plate for thermal curing to obtain an E-based PPy-NPs / polymer buried layer. 00 Mode all-optical switch (including base layer 100, first waveguide layer, composite buried layer 200, second waveguide layer, interlayer, third waveguide layer and upper cladding layer 600); the temperature of the thermal curing treatment is 120°C, and the holding time is 40 minutes to ensure that the upper cladding layer is completely cured.

[0153] Figure 6 to Figure 15 The simulation calculation diagram obtained by analyzing and calculating the all-optical switch using the finite element analysis method is described in detail below.

[0154] Figure 6 The 3D asymmetric MZI structure E is a waveguide core layer in the input region. 00 Mode-E 01Mode light coupling analysis diagram; As can be seen from the figure, after the signal light passes through the input area 200 and is transmitted through the MZI asymmetric transmission arm, the phase difference of the signal light fundamental mode changes by π, so a mode transition occurs, that is, the signal light fundamental mode is transformed into a first-order mode output, and the coupling effect reaches 90%.

[0155] Figure 7 The relationship curve between the waveguide width (waveguide core layer a width) and coupling efficiency of the 3D asymmetric MZI structure in the input region is shown in Figure 2. Figure 8 The relationship between the incident wavelength and coupling efficiency of the 3D asymmetric MZI structure with the waveguide core layer a in the input region is shown in the figure. The coupling efficiency MCE calculation formula is as follows:

[0156] MCE 1 =(P 1 / P in )×100%;

[0157] MCE 2 =[P 2 / (P 1 +P 2 )]×100%;

[0158] MCE 3 =[P 3 / (P 1 +P 3 )]×100%;

[0159] Where MCE 1 represents the asymmetric coupling region of the MZI, E 00 To E 01 Mode conversion coupling efficiency; MCE 2 represents the first coupling region, E 01 To E 00 Mode conversion coupling efficiency; MCE 3 represents the second coupling region, E 01 To E 00 Coupling efficiency of mode conversion; P 1 represents the output optical power of the 1+2 layer straight waveguide 2a 208, P 2 represents the output optical power of the waveguide core layer c, P 3 represents the output optical power of waveguide core layer b, P in Indicates the input signal optical power.

[0160] Figure 7 The waveguide width was investigated in E 00 Mode to E 01 The effect of mode transition on the coupling between TE polarization and TM polarization is Figure 7It can be seen that when the waveguide size is small, the overlap rate of the two curves is high, proving that the change of waveguide size is insensitive to the influence of polarization state. When the waveguide width is optimized to 5.1μm, the coupling efficiency reaches about 90%.

[0161] Figure 8 The wavelength of E 00 Mode to E 01 The effect of mode transition on the coupling between TE polarization and TM polarization is Figure 8 It can be seen that the change in wavelength is insensitive to the effect of the polarization state of light. When the wavelength is reduced to 1.3μm or increased to 1.8μm, the coupling efficiency drops to 0. Therefore, this structure can well isolate the signal light and the pump light, that is, when the signal light is input, E 00 Mode to E 01 When the pump light is input, it is still E 00 Mode output.

[0162] Fig. 9 E in the first coupling region 01 Mode-E 00 Mode light coupling analysis diagram, Fig.10 E in the second coupling region 01 Mode-E 00 Mode light coupling analysis diagram; the results show that E 01 After the mode signal light reaches the directional first coupling region, E 01 Mode E 00 The paradigm shift and E 00 The mode signal light is coupled into the first layer waveguide c to achieve E 00 mode signal light is output from the first layer waveguide. When E 00 After the mode pump light is applied, the PPy-NPs generate heat according to the photothermal effect, which changes the effective refractive index of the polymer material, making E 01 The mode signal light is not coupled in the first coupling region, but in the second coupling region and the third layer waveguide b, the signal light is coupled from E 01 Mode E 00 A paradigm shift. The final complete E 00 The mode signal light is output from the third layer waveguide.

[0163] Fig.11 is the relationship curve between the waveguide core layer c width and coupling efficiency, Fig.12 The graph is a graph of the relationship between the relative position Δy of the center of the waveguide core layer a and the center of the waveguide core layer c and the coupling efficiency. Both are the coupling efficiencies of the first coupling zone. The results show that when the width of the waveguide core layer c is optimized to 4.45μm, the coupling efficiency reaches the maximum value, greater than 96%; when Δy=0, the coupling efficiency is 0.

[0164] Fig.13 is the relationship curve between the waveguide core layer b width and coupling efficiency, Fig.14 The graphs are the relationship between the relative position Δx of the center of waveguide core layer a and the center of waveguide core layer b and the coupling efficiency; both are the coupling efficiencies of the second coupling zone. The results show that when the width of waveguide core layer b is optimized to 4.5μm, the coupling efficiency reaches the maximum value, which is greater than 96%; when Δx=0, the coupling efficiency is the maximum.

[0165] Fig.15 The relationship between the input power consumption and the extinction ratio at the output port of waveguide core layer b and waveguide core layer c is shown in the figure. The relationship between the extinction ratio IL and the input optical power is studied. The results show that when P in = 0mW, light is output from the waveguide core layer c, when P in =1.2 mW, light is output from the waveguide core layer b. This shows that compared with the traditional waveguide, the all-optical switch of the present invention has the advantage of low power consumption.

[0166] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An all-optical switch, characterized in that: It comprises a base layer (100), a waveguide core layer constructed on the upper surface of the base layer (100), and an upper cladding layer (600) coated outside the waveguide core layer, wherein the waveguide core layer is an asymmetric Mach-Zehnder interferometer type 1×33D waveguide core layer, and the refractive index of the waveguide core layer is higher than that of the base layer (100) and the upper cladding layer (600); Along the light incident direction, the waveguide core layer is sequentially divided into an input area (200), a first coupling area (300), a second coupling area (400) and a 3D output area (500); A composite buried layer (302) is arranged inside the waveguide core layer located in the first coupling region (300), the composite buried layer (302) comprising a polymer matrix and nanoparticles doped in the polymer matrix, and the polymer matrix and the nanoparticles are made of different materials.

2. The all-optical switch according to claim 1, characterized in that: Taking the upper surface of the base layer (100) as a reference, the waveguide core layer is provided with a first waveguide layer, a second waveguide layer and a third waveguide layer from bottom to top, the first waveguide layer includes a first waveguide layer a and a first waveguide layer c, the second waveguide layer includes a second waveguide layer a, and the third waveguide layer includes a third waveguide layer b; wherein the first waveguide a and the second waveguide a are both located in the input region (200), the first coupling region (300), the second coupling region (400) and the 3D output region (500), and the first waveguide a and the second waveguide a located in the input region (200) have a 3D asymmetric Mach-Zehnder interferometer structure, the composite buried layer (302) is arranged between the first waveguide a and the second waveguide a located in the first coupling region (300), and the first waveguide a and the second waveguide a located in the second coupling region (400) and the 3D output region (500) are arranged in a stacked arrangement; The third layer waveguide b is located in the second coupling region (400) and the 3D output region (500), and the third layer waveguide b does not contact the second layer waveguide a; along the light incident direction, the projection area of ​​the starting end of the third layer waveguide b located in the second coupling region (400) covers the second layer waveguide a below, and the projection area of ​​the third layer waveguide b located in the 3D output region (500) does not cover the second layer waveguide a; The first layer waveguide c is located in the first coupling area (300), the second coupling area (400) and the 3D output area (500), and the first layer waveguide c is not in contact with the first layer waveguide a, and the projection area of ​​the third layer waveguide b located in the 3D output area (500) and the first layer waveguide c are respectively located on both sides of the first layer waveguide a.

3. The all-optical switch according to claim 2, characterized in that: The waveguide core layer located in the input area (200) includes a 1+2 layer straight waveguide 1a (201), a 1 layer S-bend waveguide 1a (202), a 2 layer S-bend waveguide 1a (203), a 1 layer coupled arm waveguide a (204), a 2 layer coupled arm waveguide a (205), a 1 layer S-bend waveguide 2a (206), a 2 layer S-bend waveguide 2a (207) and a 1+2 layer straight waveguide 2a (208); The 1+2 layer straight waveguide 1a (201) comprises a 1st layer straight waveguide 1a and a 2nd layer straight waveguide 1a stacked in sequence from bottom to top, and the 1+2 layer straight waveguide 2a (208) comprises a 1st layer straight waveguide 2a and a 2nd layer straight waveguide 2a stacked in sequence from bottom to top; The first layer of straight waveguide 1a, the first layer of S-bend waveguide 1a (202), the first layer of coupled arm waveguide a (204), the first layer of S-bend waveguide 2a (206) and the first layer of straight waveguide 2a are connected in sequence; The second layer straight waveguide 1a, the second layer S-bend waveguide 1a (203), the second layer coupled arm waveguide a (205), the second layer S-bend waveguide 2a (207) and the second layer straight waveguide 2a are connected in sequence.

4. The all-optical switch according to claim 3, characterized in that: The waveguide core layer located in the first coupling region (300) includes a 1+2 layer straight waveguide 3a (301) and a 1 layer straight waveguide 3c (303); The 1+2 layer straight waveguide 3a (301) comprises a 1st layer straight waveguide 3a, a composite buried layer (302) and a 2nd layer straight waveguide 3a which are stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 3a (301) is connected to the 1+2 layer output straight waveguide 2a (208).

5. The all-optical switch according to claim 4, characterized in that: The waveguide core layer located in the second coupling region (400) includes a 1+2 layer straight waveguide 4a (401), a 3 layer straight waveguide 4b (402), a 3 layer S-bend waveguide 4b (403), a 1 layer S-bend waveguide 4c (404) and a 1 layer straight waveguide 4c (405); The 1+2 layer straight waveguide 4a (401) includes a 1st layer straight waveguide 4a and a 2nd layer straight waveguide 4a stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 4a (401) is connected to the 1+2 layer straight waveguide 3a (301); The first layer straight waveguide 3c (303), the first layer S-bend waveguide 4c (404) and the first layer straight waveguide 4c (405) are connected in sequence; Along the light incident direction, the third layer straight waveguide 4b (402) is connected to the third layer S-bend waveguide 4b (403) in sequence, the projection area of ​​the third layer straight waveguide 4b (402) covers the first + second layer straight waveguide 4a (401), the end projection area of ​​the third layer S-bend waveguide 4b (403) does not cover the first + second layer straight waveguide 4a (401), and the end projection area of ​​the third layer S-bend waveguide 4b (403) and the first layer straight waveguide 4c (405) are respectively located on both sides of the first + second layer straight waveguide 4a (401).

6. The all-optical switch according to claim 5, characterized in that: The waveguide core layer located in the 3D output area (500) includes a 1+2 layer straight waveguide 5a (501), a 3 layer straight waveguide 5b (502) and a 1 layer straight waveguide 5c (503); The 1+2 layer straight waveguide 5a (501) includes a 1st layer straight waveguide 5a and a 2nd layer straight waveguide 5a stacked in sequence from bottom to top; and the 1+2 layer straight waveguide 5a (501) is connected to the 1+2 layer straight waveguide 4a (401); The first layer straight waveguide 5c (503) is connected to the first layer straight waveguide 4c (405); The third layer straight waveguide 5b (502) is connected to the third layer S-bend waveguide 4b (403), and the projection area of ​​the third layer straight waveguide 5b (502) and the first layer straight waveguide 5c (503) are respectively located on both sides of the 1+2 layer straight waveguide 5a (501).

7. The all-optical switch according to any one of claims 2 to 6, characterized in that: With the light transmission plane as a reference, the first layer waveguide a, the second layer waveguide a, the first layer waveguide c and the third layer waveguide b are parallel to each other.

8. The all-optical switch according to any one of claims 2 to 6, characterized in that: The refractive index of the composite buried layer (302) is 1.57-4.

9. The all-optical switch according to claim 8, characterized in that: The nanoparticles include one or more of metal nanomaterials, carbon nanomaterials and polymer nanomaterials, and the particle size of the nanoparticles is 10-100 nm; the doping amount of the nanoparticles in the composite buried layer (302) is 0.1-5 wt‰.

10. The method for preparing the all-optical switch according to any one of claims 1 to 9, characterized in that: The following steps are involved: According to the structure of the waveguide core layer, the waveguide core layer is constructed on the upper surface of the substrate layer (100) by using a photolithography process to obtain a waveguide core layer / substrate device; The raw materials for preparing the upper cladding layer (600) are coated on the outside of the waveguide core layer in the waveguide core layer / substrate device, and the upper cladding layer (600) is formed on the outside of the waveguide core layer through thermal curing to obtain the all-optical switch.

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