A silicon oxide waveguide optical switch and its manufacturing method

Abstract

This invention discloses a silicon oxide waveguide optical switch device and its fabrication method. The silicon oxide waveguide optical switch device includes a waveguide core layer, an upper cladding layer, a lower cladding layer, and a heating electrode. A cover plate is disposed on the upper cladding layer and the heating electrode. A heat dissipation channel structure is disposed from the upper surface of the cover plate and extends downward into the interior of the lower cladding layer. The heat dissipation channel structure is located on the front side of the waveguide core layer. The heat dissipation channel structure includes a fluid inlet, a fluid outlet, and a fluid channel. The fluid inlet and the fluid outlet are both cylindrical cavities that extend downward from the upper surface of the cover plate into the interior of the cover plate. The axis of the cylindrical cavity is along the vertical direction. The fluid inlet and the fluid outlet are spaced apart on the left and right. The fluid channel extends from the interior of the cover plate into the interior of the lower cladding layer, and its two ends are located below the fluid inlet and the fluid outlet, respectively, and are vertically connected to the fluid inlet and the fluid outlet. The advantages are high heat dissipation efficiency and fast switching speed.

Description

Technical Field

[0001] This invention relates to waveguide optical switches, and more particularly to a silicon oxide waveguide optical switch and its manufacturing method. Background Technology

[0002] Optical switches are core components in the field of optical communication. Their core function is to switch optical signals between different optical paths, playing an important role in optical network applications such as optical cross-connectors and optical add-drop multiplexers.

[0003] Existing optical switches typically include silicon-based waveguide optical switches (optical switches fabricated based on silicon-based waveguides), polymer waveguide optical switches (optical switches fabricated based on polymer waveguides), silicon oxide waveguide optical switches (optical switches fabricated based on silicon oxide waveguides), and microelectromechanical optical switches (optical switches fabricated based on microelectromechanical systems). Among them, silicon oxide waveguide optical switches have attracted widespread attention from academia and industry due to their low loss, high temperature stability, and low cost.

[0004] Traditional silicon oxide waveguide optical switches typically consist of a waveguide core layer for optical switching, an upper cladding layer, and a lower cladding layer that completely enclose the waveguide core layer. Optical path switching is achieved by changing the refractive index of the waveguide core layer. Both the upper and lower cladding layers are made of silicon oxide, while the waveguide core layer is made of doped silicon oxide, with the doped silicon oxide used for the waveguide core layer having a refractive index 0.5%-2% higher than that used for the upper and lower cladding layers. In traditional silicon oxide waveguide optical switches, due to the small refractive index difference between the waveguide core layer and the upper and lower cladding layers, the upper and lower cladding layers are typically quite thick (generally not less than 10 μm) to ensure waveguide mode confinement. The thickness of the upper and lower cladding layers directly affects the heat dissipation efficiency of the silicon oxide waveguide optical switch, which in turn directly affects the switching speed; that is, the greater the thickness, the lower the heat dissipation efficiency and the lower the switching speed. Therefore, traditional silicon oxide waveguide optical switches have poor heat dissipation efficiency, resulting in a switching speed of only milliseconds, which seriously affects their application in optical interconnection, optical switching and other scenarios. Summary of the Invention

[0005] One of the technical problems to be solved by the present invention is to provide a silicon oxide waveguide optical switch with high heat dissipation efficiency and fast switching speed.

[0006] The technical solution adopted by the present invention to solve one of the above-mentioned technical problems is as follows: a silicon oxide waveguide optical switch device, comprising a waveguide core layer, an upper cladding layer, a lower cladding layer, and a heating electrode for realizing optical switching function. The waveguide core layer is disposed on the upper surface of the lower cladding layer, and the heating electrode is disposed on the upper surface of the upper cladding layer for heating the waveguide core layer to change its refractive index and realize optical path switching. The upper cladding layer and the lower cladding layer are both made of silicon oxide, and the waveguide core layer is made of doped silicon oxide with a refractive index higher than that of silicon oxide. A cover plate is disposed on the upper cladding layer and the heating electrode to completely cover them. A downward extension from the upper surface of the cover plate to the lower cladding layer is provided. The heat dissipation channel structure inside the layer is located on the front side of the waveguide core layer. The heat dissipation channel structure includes a fluid inlet, a fluid outlet, and a fluid channel. The fluid inlet and the fluid outlet both start from the upper surface of the cover plate and extend downward to a cylindrical cavity inside the cover plate. The axis of the cylindrical cavity is along the vertical direction. The fluid inlet and the fluid outlet are spaced apart on the left and right. The fluid channel extends from the inside of the cover plate to the inside of the lower cladding layer, and its two ends are located below the fluid inlet and the fluid outlet, respectively, and are vertically connected to the fluid inlet and the fluid outlet in a one-to-one correspondence.

[0007] Compared with the prior art, the advantage of the silicon oxide waveguide optical switch of the present invention lies in that a cover plate is provided on the upper cladding and the heating electrode to completely cover both. A heat dissipation channel structure is provided from the upper surface of the cover plate and extends downward into the interior of the lower cladding. The heat dissipation channel structure is located on the front side of the waveguide core layer. The heat dissipation channel structure includes a fluid inlet, a fluid outlet, and a fluid channel. The fluid inlet and the fluid outlet are both cylindrical cavities that extend downward from the upper surface of the cover plate into the interior of the cover plate. The axis of the cylindrical cavity is along the vertical direction. The fluid inlet and the fluid outlet are spaced apart from each other on the left and right. The fluid channel extends from the interior of the cover plate. Extending into the lower cladding layer, with its two ends located below the fluid inlet and outlet respectively, it is vertically connected to the fluid inlet and outlet. When the silicon oxide waveguide optical switch is working, the cooling liquid flows into the fluid inlet through the pipe, then flows through the fluid channel, and finally flows out through the fluid outlet. During the flow of the liquid in the fluid channel, it exchanges heat with the side wall of the fluid channel, which will carry away the heat inside the silicon oxide waveguide optical switch device, thereby achieving cooling and heat dissipation of the silicon oxide waveguide optical switch device. Thus, the silicon oxide waveguide optical switch device of the present invention has high heat dissipation efficiency and fast switching speed.

[0008] Furthermore, the fluid channel includes a first flow channel, a second flow channel, and a third flow channel. Each of these three flow channels is a square cavity extending downwards from the inside of the cover plate into the inside of the lower cladding layer. The first flow channel is located below the fluid inlet and is vertically connected to it. The third flow channel is located below the fluid outlet and is vertically connected to it. The second flow channel is located between the first and third flow channels and is connected to both of them. When liquid flows into the fluid inlet through the pipe, it flows sequentially through the first, second, and third flow channels, and finally exits through the fluid outlet. During the flow of liquid through the first, second, and third flow channels, it carries away heat from the silicon oxide waveguide optical switch device, thus achieving cooling and heat dissipation of the silicon oxide waveguide optical switch device.

[0009] Furthermore, the material of the cover plate is a polydimethylsiloxane (PDMS) mixture, which is formed by uniformly mixing PDMS and curing agent at a weight ratio of 10:1; the doped silicon oxide is germanium-doped silicon oxide or nitrogen-doped silicon oxide.

[0010] Furthermore, the waveguide core layer is implemented using a Mach-Zehnder interferometer structure.

[0011] Furthermore, the waveguide core layer includes two input waveguides, two 3dB couplers, two phase-shifting arm waveguides, and two output waveguides. Each 3dB coupler has two input terminals and two output terminals, referred to as its first input terminal and second input terminal, and its two output terminals as its first output terminal and second output terminal, respectively. The first input terminal of each 3dB coupler is directly connected to its first output terminal, and the second input terminal is directly connected to its second output terminal. The two input waveguides are referred to as the first input waveguide and the second input waveguide, the two 3dB couplers as the first coupler and the second coupler, the two phase-shifting arm waveguides as the first phase-shifting arm waveguide and the second phase-shifting arm waveguide, and the two output waveguides as the first output waveguide and the second output waveguide, respectively. One end of the first input waveguide and one end of the second input waveguide are both used for connection to external... The optical signal is generated by a first input waveguide, the other end of which is connected to the first input terminal of the first coupler; the other end of the second input waveguide is connected to the second input terminal of the first coupler; the first output terminal of the first coupler is connected to one end of the first phase-shifting arm waveguide; the second output terminal of the first coupler is connected to one end of the second phase-shifting arm waveguide; the other end of the first phase-shifting arm waveguide is connected to the first input terminal of the second coupler; the other end of the second phase-shifting arm waveguide is connected to the second input terminal of the second coupler; the first output terminal of the second coupler is connected to one end of the first output waveguide; and the second output terminal of the second coupler is connected to one end of the second output waveguide. Both the other ends of the first and second output waveguides are used to output optical signals.

[0012] Furthermore, a heat insulation groove is provided between the first phase-shifting arm waveguide and the second phase-shifting arm waveguide to prevent heat diffusion and improve thermal tuning efficiency. The heat insulation groove is a square cavity that extends downward from the upper end face of the upper cladding to the interior of the lower cladding.

[0013] Furthermore, the heating electrode includes a heating resistance wire and two metal electrodes. The heating resistance wire is located directly above the first phase-shifting arm waveguide, and the two metal electrodes are respectively connected to both ends of the heating resistance wire for connection to an external power source to supply power to the heating resistance wire.

[0014] Furthermore, both metal electrodes are made of Al or Au.

[0015] The second technical problem to be solved by the present invention is to provide a method for manufacturing a silicon oxide waveguide optical switch. The silicon oxide waveguide optical switch manufactured by this method has high heat dissipation efficiency and fast switching speed.

[0016] The technical solution adopted by this invention to solve the second technical problem mentioned above is: a method for manufacturing a silicon oxide waveguide optical switch device, comprising the following steps:

[0017] Step 1: Select a silicon wafer or quartz wafer with a silicon oxide material layer of more than 10 μm on its surface, and use this silicon oxide material layer as the lower cladding layer;

[0018] Step 2: Grow doped silicon oxide on the upper surface of the lower cladding layer to form a doped silicon oxide layer, and perform annealing treatment to relieve stress;

[0019] Step 3: A mask for forming the waveguide core layer is formed on the doped silicon oxide layer by photolithography, and the doped silicon oxide layer is etched by inductively coupled plasma etching process to form the waveguide core layer;

[0020] Step 4: Chemical vapor deposition of silicon dioxide to form the upper cladding layer on the lower cladding layer and the waveguide core layer;

[0021] Step 5: Install heating electrodes on the upper cladding layer;

[0022] Step 6: Spin-coat photoresist onto the upper cladding and heating electrodes. Photolithography forms a portion of the structure where the fluid channel is located within the upper and lower cladding, as well as a mask for the heat insulation groove used to prevent heat diffusion from the waveguide core layer and improve thermal tuning efficiency. The upper and lower cladding are etched using inductively coupled plasma etching to form a portion of the structure where the fluid channel is located within the upper and lower cladding, as well as the heat insulation groove. The structure obtained at this point is called the first part of the structure.

[0023] Step 7: Create a mask pattern of a portion of the structure with fluid channels on the cover plate, spin-coat photoresist on the base plate, transfer the mask pattern onto the photoresist by ultraviolet exposure, and form a positive mold of a portion of the structure with fluid channels on the cover plate after development.

[0024] Step 8: Mix PDMS and curing agent at a weight ratio of 10:1 and stir until homogeneous. Remove air bubbles in a vacuum to obtain a PDMS mixture.

[0025] Step 9: Wrap the outer edge of the male mold with aluminum foil, pour the PDMS mixture onto the surface of the male mold, and bake it on a heating table to cure the PDMS mixture;

[0026] Step 10: Peel the cured PDMS mixture from the male mold. At this point, the cured PDMS mixture forms a cover plate, and the peeled area of ​​the male mold forms a fluid channel located on a part of the cover plate.

[0027] Step 11: Use a punch to punch holes in the cover plate to form a fluid inlet and a fluid outlet that are connected to the fluid channel. The structure obtained at this time is called the second part of the structure.

[0028] Step 12: Align and bond the second part of the structure with the first part of the structure to obtain the silicon oxide waveguide optical switch device.

[0029] Compared with the prior art, the manufacturing method of the silicon oxide waveguide optical switch of the present invention has the advantage of combining etching and deposition processes to obtain a silicon oxide waveguide optical switch device with an internal heat dissipation channel structure. This heat dissipation channel structure includes a fluid inlet, a fluid outlet, and a fluid channel. Both the fluid inlet and outlet are cylindrical cavities extending downwards from the upper surface of the cover plate into the interior of the cover plate. The axis of the cylindrical cavity is along the vertical direction. The fluid inlet and outlet are spaced apart horizontally. The fluid channel extends from the interior of the cover plate into the interior of the lower cladding, with its two ends located at the fluid inlet and outlet. Below the inlet and fluid outlet, there are vertical connections that correspond one-to-one with the fluid inlet and fluid outlet. When the silicon oxide waveguide optical switch is working, the cooling liquid flows into the fluid inlet through the pipe, then flows through the fluid channel, and finally flows out through the fluid outlet. During the flow of the liquid in the fluid channel, it exchanges heat with the side wall of the fluid channel, which will carry away the heat inside the silicon oxide waveguide optical switch device, thereby achieving cooling and heat dissipation of the silicon oxide waveguide optical switch device. Therefore, the silicon oxide waveguide optical switch manufactured by the manufacturing method of the present invention has high heat dissipation efficiency and fast switching speed.

[0030] Furthermore, the photoresist in step 7 is SU8 photoresist, and the thickness of the photoresist is 40μm. Attached Figure Description

[0031] Figure 1 This is a top view (internal structure perspective) of the silicon oxide waveguide optical switch device of the present invention;

[0032] Figure 2 for Figure 1 Cross-sectional view at section 1 along the middle section;

[0033] Figure 3 for Figure 1 Cross-sectional view at section 2 along the middle section;

[0034] Figure 4 This is a flowchart of the first part of the manufacturing method of the silicon oxide waveguide optical switch device of the present invention;

[0035] Figure 5 This is a flowchart of the latter part of the manufacturing method of the silicon oxide waveguide optical switch device of the present invention;

[0036] Figure 6 The diagram shows the heat dissipation efficiency of the silicon oxide waveguide optical switch device of the present invention under different liquid flow rates. Detailed Implementation

[0037] This invention discloses a silicon oxide waveguide optical switch device. The following describes the silicon oxide waveguide optical switch device of this invention in further detail with reference to the accompanying drawings and embodiments.

[0038] Example 1: As Figures 1 to 3 As shown, a silicon oxide waveguide optical switch device includes a waveguide core layer, an upper cladding layer 1, a lower cladding layer 2, and a heating electrode for realizing optical switching function. The waveguide core layer is disposed on the upper surface of the lower cladding layer 2, and the heating electrode is disposed on the upper surface of the upper cladding layer 1 for heating the waveguide core layer, thereby changing its refractive index to achieve optical path switching. The upper cladding layer 1 and the lower cladding layer 2 are both made of silicon oxide, and the waveguide core layer is made of doped silicon oxide with a refractive index higher than that of silicon oxide. A cover plate 5 is disposed on the upper cladding layer 1 and the heating electrode to completely cover them. A grommets extending downward from the upper surface of the cover plate 5 into the lower cladding layer 2 are provided. The heat dissipation channel structure is located on the front side of the waveguide core layer. The heat dissipation channel structure includes a fluid inlet 3, a fluid outlet 4, and a fluid channel. Both the fluid inlet 3 and the fluid outlet 4 are cylindrical cavities that extend downward from the upper surface of the cover plate 5 into the interior of the cover plate 5. The axis of the cylindrical cavity is along the vertical direction. The fluid inlet 3 and the fluid outlet 4 are spaced apart on the left and right. The fluid channel extends from the interior of the cover plate 5 into the interior of the lower cladding layer 2, and its two ends are located below the fluid inlet 3 and the fluid outlet 4, respectively, and are connected vertically to the fluid inlet 3 and the fluid outlet 4.

[0039] In this embodiment, when the silicon oxide waveguide optical switch is working, the cooling liquid flows into the fluid inlet 3 through the pipe, then flows through the fluid channel, and finally flows out through the fluid outlet 4. During the flow of the liquid in the fluid channel, it exchanges heat with the side wall of the fluid channel, which will carry away the heat inside the silicon oxide waveguide optical switch device, thereby achieving cooling and heat dissipation of the silicon oxide waveguide optical switch device and improving its switching speed.

[0040] Example 2: This example is basically the same as Example 1, except that: In this example, the fluid channel includes a first flow channel 6, a second flow channel 7, and a third flow channel 8. The first flow channel 6, the second flow channel 7, and the third flow channel 8 are all square cavities that extend downward from the inside of the cover plate 5 to the inside of the lower cladding layer 2. The first flow channel 6 is located below the fluid inlet 3 and is vertically connected to the fluid inlet 3. The third flow channel 8 is located below the fluid outlet 4 and is vertically connected to the fluid outlet 4. The second flow channel 7 is located between the first flow channel 6 and the third flow channel 8 and is vertically connected to both the first flow channel 6 and the third flow channel 8.

[0041] In this embodiment, when liquid flows into fluid inlet 3 through the pipe, the liquid flows through the first channel 6, the second channel 7 and the third channel 8 in sequence, and finally flows out through fluid outlet 4. During the flow of liquid through the first channel 6, the second channel 7 and the third channel 8, heat exchange occurs with the sidewalls of the first channel 6, the second channel 7 and the third channel 8, which will carry away the internal heat of the silicon oxide waveguide optical switch device, thereby achieving cooling and heat dissipation of the silicon oxide waveguide optical switch device.

[0042] In this embodiment, the first flow channel 6, the second flow channel 7, and the third flow channel 8 can be integrally formed by etching, which has low process requirements.

[0043] Example 3: This example is basically the same as Example 2, except that: in this example, the material of the cover plate 5 is a mixture of polydimethylsiloxane (PDMS), which is formed by uniformly mixing PDMS and curing agent at a weight ratio of 10:1; the doped silicon oxide is germanium-doped silicon oxide or nitrogen-doped silicon oxide.

[0044] Example 4: This example is basically the same as Example 2, except that the waveguide core layer is implemented using a Mach-Zehnder interferometer structure.

[0045] In this embodiment, the waveguide core layer includes two input waveguides, two 3dB couplers, two phase-shifting arm waveguides, and two output waveguides. Each 3dB coupler has two input terminals and two output terminals. The two input terminals are referred to as its first input terminal and second input terminal, and the two output terminals are referred to as its first output terminal and second output terminal, respectively. The first input terminal of each 3dB coupler is directly connected to its first output terminal, and the second input terminal is directly connected to its second output terminal. The two input waveguides are referred to as first input waveguide 9 and second input waveguide 10, respectively. The two 3dB couplers are referred to as first coupler 11 and second coupler 12, respectively. The two phase-shifting arm waveguides are referred to as first phase-shifting arm waveguide 13 and second phase-shifting arm waveguide 14, respectively. The two output waveguides are referred to as first output waveguide 15 and second output waveguide 16, respectively. One end of the first input waveguide 9 and the second... One end of each input waveguide 10 is used to receive external optical signals. The other end of the first input waveguide 9 is connected to the first input terminal of the first coupler 11. The other end of the second input waveguide 10 is connected to the second input terminal of the first coupler 11. The first output terminal of the first coupler 11 is connected to one end of the first phase-shifting arm waveguide 13. The second output terminal of the first coupler 11 is connected to one end of the second phase-shifting arm waveguide 14. The other end of the first phase-shifting arm waveguide 13 is connected to the first input terminal of the second coupler 12. The other end of the second phase-shifting arm waveguide 14 is connected to the second input terminal of the second coupler 12. The first output terminal of the second coupler 12 is connected to one end of the first output waveguide 15. The second output terminal of the second coupler 12 is connected to one end of the second output waveguide 16. The other ends of the first output waveguide 15 and the second output waveguide 16 are both used to output optical signals.

[0046] In this embodiment, a heat insulation groove 17 is provided between the first phase-shifting arm waveguide 13 and the second phase-shifting arm waveguide 14 to avoid heat diffusion and improve thermal tuning efficiency. The heat insulation groove 17 is a square cavity that extends downward from the upper end face of the upper cladding 1 to the interior of the lower cladding 2.

[0047] In this embodiment, the heating electrode includes a heating resistance wire 18 and two metal electrodes 19. The heating resistance wire 18 is located directly above the first phase-shifting arm waveguide 13. The two metal electrodes 19 are respectively connected to the two ends of the heating resistance wire 18 for connection to an external power source to supply power to the heating resistance wire 18.

[0048] In this embodiment, the materials of both metal electrodes 19 are Al or Au.

[0049] In this embodiment, the first coupler 11 can evenly distribute the optical signal input from the first input waveguide 9 or the second input waveguide 10 into the first phase-shifting arm waveguide 13 and the second phase-shifting arm waveguide 14. The second coupler 12 can evenly distribute the optical signal output from the first phase-shifting arm waveguide 13 or the second phase-shifting arm waveguide 14 into the first output waveguide 15 and the second output waveguide 16. By energizing the two metal electrodes 19, the heating resistance wire 18 heats the first phase-shifting arm waveguide 13, changing the phase of the first phase-shifting arm waveguide 13, thereby changing the light transmission path in the optical switch and realizing optical path switching. When the heating resistance wire 18 heats the first phase-shifting arm waveguide 13, causing the phase of the first phase-shifting arm waveguide 13 to be in the interference state of the two optical paths within the first output waveguide 15, the optical path can be transmitted from the first input waveguide 9 to the first output waveguide 15 or from the second input waveguide 10 to the second output waveguide 16, i.e., the cross state. When the heating resistance wire 18 heats the first phase-shifting arm waveguide 13, causing the phase of the first phase-shifting arm waveguide 13 to be in the interference state of the two optical paths within the second output waveguide 16, the optical path can be transmitted from the first input waveguide 9 to the second output waveguide 16 or from the second input waveguide 10 to the first output waveguide 15, i.e., the bar state.

[0050] The present invention also discloses a method for manufacturing the silicon oxide waveguide optical switch device described above. The method for manufacturing the silicon oxide waveguide optical switch device of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0051] Example: Figure 4 and 5 As shown, a method for manufacturing a silicon oxide waveguide optical switch device includes the following steps:

[0052] Step 1: Select a silicon wafer or quartz wafer with a silicon oxide material layer of more than 10 μm on its surface, and use the silicon oxide material layer as the lower cladding layer 2;

[0053] Step 2: Grow doped silicon oxide on the upper surface of the lower cladding layer 2 to form a doped silicon oxide layer, and perform annealing treatment to relieve stress;

[0054] Step 3: A mask for forming the waveguide core layer is formed on the doped silicon oxide layer by photolithography, and the doped silicon oxide layer is etched by inductively coupled plasma etching process to form the waveguide core layer;

[0055] Step 4: Chemical vapor deposition of silicon dioxide to form upper cladding 1 on lower cladding 2 and waveguide core layer;

[0056] Step 5: Set heating electrodes on the upper cladding layer 1;

[0057] Step 6: Spin-coat photoresist onto the upper cladding layer 1 and the heating electrode. Photolithography forms a partial structure with fluid channels located within the upper cladding layer 1 and the lower cladding layer 2, as well as a mask for the heat insulation groove 17 used to prevent heat diffusion from the waveguide core layer and improve thermal tuning efficiency. The upper cladding layer 1 and the lower cladding layer 2 are etched using an inductively coupled plasma etching process to form a partial structure with fluid channels located within the upper cladding layer 1 and the lower cladding layer 2, as well as the heat insulation groove 17. The structure obtained at this time is called the first partial structure.

[0058] Step 7: Create a mask pattern of a portion of the structure with fluid channels on cover plate 5, spin-coat photoresist on the base plate, transfer the mask pattern onto the photoresist by ultraviolet exposure, and form a positive mold of a portion of the structure with fluid channels on cover plate 5 after development.

[0059] Step 8: Mix PDMS and curing agent at a weight ratio of 10:1 and stir until homogeneous. Remove air bubbles in a vacuum to obtain a PDMS mixture.

[0060] Step 9: Wrap the outer edge of the male mold with aluminum foil, pour the PDMS mixture onto the surface of the male mold, and bake it on a heating table to cure the PDMS mixture;

[0061] Step 10: Peel the cured PDMS mixture from the male mold. At this time, the cured PDMS mixture forms a cover plate 5, and the peeled part of the male mold forms a fluid channel on the cover plate 5.

[0062] Step 11: Use a punch to punch holes in the cover plate 5 to form a fluid inlet 3 and a fluid outlet 4 that are connected to the fluid channel. The structure obtained at this time is called the second part structure.

[0063] Step 12: Align and bond the second part of the structure with the first part of the structure to obtain the silicon oxide waveguide optical switch device.

[0064] In this embodiment, the photoresist in step 7 is SU8 photoresist, and the thickness of the photoresist is 40μm.

[0065] To verify the performance of the silicon oxide waveguide optical switch device and its manufacturing method of the present invention, simulations were performed on the silicon oxide waveguide optical switch device of the present invention. During the simulation, the lower cladding layer 2 was made of quartz material, which has poor heat dissipation. The second flow channel 7 has a width of 100 μm along the front-to-back direction. A portion of the first flow channel 6, the second flow channel 7, and the third flow channel 8 within the upper cladding layer 1 and the lower cladding layer 2 each has a depth of 40 μm along the vertical direction, and a portion within the cover plate 5 also has a depth of 40 μm along the vertical direction. The width and height of each waveguide in the waveguide core layer are 3.4 μm. The heating electrode is located 10 μm directly above the waveguide core layer. The horizontal distance between the second flow channel 7 and the waveguide core layer is 5 μm. The thermal conductivity of the silicon oxide material was set to 1.4 [W / (m*K)]. The simulation showed a temperature jump of the heating electrode from 400 K to 290 K, yielding the following results: Figure 6 The diagram shows the heat dissipation efficiency of the silicon oxide waveguide optical switch device of the present invention under different liquid flow rates. Figure 6 In this context, Q represents the cooling fluid flow rate. Analysis Figure 6 It can be seen that during the process of increasing liquid flow rate in the heat dissipation channel structure, the temperature drop time of the silicon oxide waveguide optical switch device is significantly reduced, and can be reduced to the submicron level, which is far higher than the heat dissipation efficiency of a simple quartz-based waveguide.

[0066] In summary, the silicon oxide waveguide optical switch device of the present invention achieves cooling and heat dissipation by setting a heat dissipation channel structure to allow the cooling liquid to circulate and dissipate heat through the flow of liquid. It has high heat dissipation efficiency, fast switching speed, and has broad application prospects in optical interconnection, optical switching and other scenarios.

Claims

1. A silicon oxide waveguide optical switch device, comprising a waveguide core layer, an upper cladding layer, a lower cladding layer, and a heating electrode for realizing optical switching function, wherein the waveguide core layer is disposed on the upper surface of the lower cladding layer, and the heating electrode is disposed on the upper surface of the upper cladding layer for heating the waveguide core layer to change its refractive index and achieve optical path switching, wherein the upper cladding layer and the lower cladding layer are both made of silicon oxide, and the waveguide core layer is made of doped silicon oxide with a refractive index higher than that of silicon oxide, characterized in that... The upper cladding and the heating electrode are provided with cover plates that completely cover them. A heat dissipation channel structure is provided from the upper surface of the cover plate and extends downward into the interior of the lower cladding. The heat dissipation channel structure is located on the front side of the waveguide core layer. The heat dissipation channel structure includes a fluid inlet, a fluid outlet, and a fluid channel. The fluid inlet and the fluid outlet are both cylindrical cavities that extend downward from the upper surface of the cover plate into the interior of the cover plate. The axis of the cylindrical cavity is along the vertical direction. The fluid inlet and the fluid outlet are spaced apart from each other on the left and right. The fluid channel extends from the interior of the cover plate into the interior of the lower cladding, and its two ends are located below the fluid inlet and the fluid outlet, respectively, and are vertically connected to the fluid inlet and the fluid outlet in a one-to-one correspondence.

2. The silicon oxide waveguide optical switch device according to claim 1, characterized in that... The fluid channel includes a first channel, a second channel, and a third channel. Each of these channels is a square cavity extending downwards from the inside of the cover plate into the lower cladding layer. The first channel is located below the fluid inlet and is vertically connected to it. The third channel is located below the fluid outlet and is vertically connected to it. The second channel is located between the first and third channels and is connected to both. When liquid flows into the fluid inlet through the pipes, it flows sequentially through the first, second, and third channels, finally exiting through the fluid outlet. During the flow of liquid through these channels, it carries away heat from the silicon oxide waveguide optical switch device, thus achieving cooling and heat dissipation.

3. The silicon oxide waveguide optical switch device according to claim 1, characterized in that... The cover plate is made of a polydimethylsiloxane (PDMS) mixture, which is formed by uniformly mixing PDMS and a curing agent at a weight ratio of 10:1; the doped silicon oxide is germanium-doped silicon oxide or nitrogen-doped silicon oxide.

4. The silicon oxide waveguide optical switch device according to claim 2, characterized in that... The waveguide core layer is implemented using a Mach-Zehnder interferometer structure.

5. A silicon oxide waveguide optical switch device according to claim 2, characterized in that... The waveguide core layer comprises two input waveguides, two 3dB couplers, two phase-shifting arm waveguides, and two output waveguides. Each 3dB coupler has two input terminals and two output terminals, referred to as its first input terminal and second input terminal, and its two output terminals as its first output terminal and second output terminal, respectively. The first input terminal of each 3dB coupler is directly connected to its first output terminal, and the second input terminal is directly connected to its second output terminal. The two input waveguides are referred to as the first input waveguide and the second input waveguide, the two 3dB couplers as the first coupler and the second coupler, the two phase-shifting arm waveguides as the first phase-shifting arm waveguide and the second phase-shifting arm waveguide, and the two output waveguides as the first output waveguide and the second output waveguide, respectively. One end of each of the first and second input waveguides is used to connect to external light. The signal is transmitted through a first input waveguide, the other end of which is connected to the first input terminal of the first coupler; the other end of the second input waveguide is connected to the second input terminal of the first coupler; the first output terminal of the first coupler is connected to one end of the first phase-shifting arm waveguide; the second output terminal of the first coupler is connected to one end of the second phase-shifting arm waveguide; the other end of the first phase-shifting arm waveguide is connected to the first input terminal of the second coupler; the other end of the second phase-shifting arm waveguide is connected to the second input terminal of the second coupler; the first output terminal of the second coupler is connected to one end of the first output waveguide; and the second output terminal of the second coupler is connected to one end of the second output waveguide. Both the other ends of the first and second output waveguides are used to output optical signals.

6. A silicon oxide waveguide optical switch device according to claim 5, characterized in that... A heat insulation groove is provided between the first phase-shifting arm waveguide and the second phase-shifting arm waveguide to prevent heat diffusion and improve thermal tuning efficiency. The heat insulation groove is a square cavity that extends downward from the upper end face of the upper cladding to the interior of the lower cladding.

7. A silicon oxide waveguide optical switch device according to claim 5, characterized in that... The heating electrode includes a heating resistance wire and two metal electrodes. The heating resistance wire is located directly above the first phase-shifting arm waveguide. The two metal electrodes are respectively connected to the two ends of the heating resistance wire for connection to an external power source to supply power to the heating resistance wire.

8. A silicon oxide waveguide optical switch device according to claim 7, characterized in that... Both metal electrodes are made of Al or Au.

9. A method for manufacturing a silicon oxide waveguide optical switch device according to any one of claims 1-8, characterized in that... Includes the following steps: Step 1: Select a silicon wafer or quartz wafer with a silicon oxide material layer of more than 10 μm on its surface, and use this silicon oxide material layer as the lower cladding layer; Step 2: Grow doped silicon oxide on the upper surface of the lower cladding layer to form a doped silicon oxide layer, and perform annealing treatment to relieve stress; Step 3: A mask for forming the waveguide core layer is formed on the doped silicon oxide layer by photolithography, and the doped silicon oxide layer is etched by inductively coupled plasma etching process to form the waveguide core layer; Step 4: Chemical vapor deposition of silicon dioxide to form the upper cladding layer on the lower cladding layer and the waveguide core layer; Step 5: Install heating electrodes on the upper cladding layer; Step 6: Spin-coat photoresist onto the upper cladding and heating electrodes, and use photolithography to form a part of the structure of the fluid channel located in the upper and lower cladding, as well as a heat insulation trench mask used to avoid heat diffusion from the waveguide core layer and improve thermal tuning efficiency. Complete the etching of the upper and lower cladding through inductively coupled plasma etching process to form a part of the structure of the fluid channel located in the upper and lower cladding and the heat insulation trench. The structure obtained at this point is called the first part of the structure; Step 7: Create a mask pattern of a portion of the structure with fluid channels on the cover plate, spin-coat photoresist on the base plate, transfer the mask pattern onto the photoresist by ultraviolet exposure, and form a positive mold of a portion of the structure with fluid channels on the cover plate after development. Step 8: Mix PDMS and curing agent at a weight ratio of 10:1 and stir until homogeneous. Remove air bubbles in a vacuum to obtain a PDMS mixture. Step 9: Wrap the outer edge of the male mold with aluminum foil, pour the PDMS mixture onto the surface of the male mold, and bake it on a heating table to cure the PDMS mixture; Step 10: Peel the cured PDMS mixture from the male mold. At this point, the cured PDMS mixture forms a cover plate, and the peeled area of ​​the male mold forms a fluid channel located on a part of the cover plate. Step 11: Use a punch to punch holes in the cover plate to form a fluid inlet and a fluid outlet that are connected to the fluid channel. The structure obtained at this time is called the second part of the structure. Step 12: Align and bond the second part of the structure with the first part of the structure to obtain the silicon oxide waveguide optical switch device.

10. The method for manufacturing a silicon oxide waveguide optical switch device according to claim 9, characterized in that... The photoresist used in step 7 is SU8 photoresist with a thickness of 40 μm.

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