Low pump light power controlled all-optical router and preparation method and application thereof

Abstract

The application discloses a kind of low pump light power control all-optical router and its preparation method and application, it is by base, metal waveguide layer, insulating layer and metal nanostructure Composition, metal waveguide layer is opened with Y type groove, Y type groove is filled with transparent conductive oxide, metal nanostructure includes first nanometer metal block and second nanometer metal block, respectively located Y type groove first branch groove section and the top of second branch groove section;Advantages are that different thickness nanometer metal block is selectively excited by different wavelength pump light, local surface plasmon and local electric field are generated, and then the electron concentration distribution of corresponding branch groove section in transparent conductive oxide is regulated, signal light absorption loss is changed, the routing control of signal light between different branches of Y type groove is realized, with low pump light power, fast response speed, large modulation depth, not sensitive to process error and temperature fluctuation, preparation process is simple and easy to integrate and the like.

Description

Technical Field

[0001] This invention relates to the field of optical communication, and in particular to an all-optical router with low pump power control, its fabrication method, and its application. Background Technology

[0002] With the rapid development of artificial intelligence, big data, and photonic integrated chip technology, global data traffic is growing exponentially, placing extremely high demands on the bandwidth and latency of communication networks. As a core network component, the performance of routers directly affects communication quality. Traditional electrical domain routers require "optical-electrical-optical" conversion, which suffers from high latency, high energy consumption, susceptibility to electromagnetic interference, and difficulty in integration. Therefore, all-optical routers that do not require photoelectric conversion have become a research hotspot.

[0003] Currently, the mainstream implementation schemes for all-optical routers mainly include three categories: semiconductor optical amplifiers, microring resonators, and photonic crystals. Among them, the semiconductor optical amplifier scheme is limited by carrier recovery time, making it difficult to improve response speed and resulting in high energy consumption; the microring resonator scheme is extremely sensitive to wavelength, and process errors and temperature fluctuations can easily lead to routing failures, requiring complex wavelength locking mechanisms; while the photonic crystal scheme has the potential for ultra-small size and fast response, its complex fabrication process and high coupling loss hinder its practical application. In recent years, all-optical router devices based on transparent conductive oxides (such as indium tin oxide (ITO), zinc oxide (ZnO), and cadmium oxide (CdO)) have utilized their near-zero dielectric constant in the near-infrared band for carrier modulation, providing a new approach to achieving high-speed routing with compact structures. However, existing research still largely relies on the optical response of materials, resulting in significant bottlenecks in energy consumption and response speed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an all-optical router with low pump power control, its fabrication method and application, which not only reduces the required pump power, but also has the advantages of fast response speed and small overall device size.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a low-pump optical power controlled all-optical router, comprising a substrate, a metal waveguide layer, an insulating layer, and a metal nanostructure arranged and fixed from bottom to top. The metal waveguide layer has Y-shaped trenches, and the Y-shaped trenches are filled with transparent conductive oxides. The metal nanostructure includes a first nano-metal block and a second nano-metal block. The Y-shaped trench includes a main trench segment and a first branch trench segment and a second branch trench segment extending horizontally from the end of the main trench segment. The first nano-metal block is fixedly disposed on the insulating layer at a position corresponding to the first branch trench segment in the vertical direction, and the second nano-metal block is fixedly disposed on the insulating layer at a position corresponding to the second branch trench segment in the vertical direction.

[0006] Compared with existing technologies, the advantages of this invention lie in its use of a substrate, a metal waveguide layer, an insulating layer, and a metal nanostructure arranged sequentially from bottom to top. The metal waveguide layer has Y-shaped trenches filled with transparent conductive oxide. Two nano-metal blocks of different thicknesses are respectively placed above the two branch trench sections. During operation, pump light of different wavelengths selectively excites the nano-metal blocks of corresponding thicknesses, generating localized surface plasmons and forming a strong localized electric field. This localized electric field directly regulates the electron concentration distribution of the corresponding branch in the transparent conductive oxide. Utilizing the near-zero dielectric constant of the transparent conductive oxide in the near-infrared band, the absorption loss of the signal light is altered, thereby controlling the signal light output from different branches of the Y-shaped trench. This avoids the "optical-electrical-optical" conversion of traditional electronically controlled routers, fundamentally reducing latency and energy consumption. Simultaneously, since routing switching relies on wavelength-selective localized plasmon excitation rather than the resonant wavelength of the micro-ring resonator, it is less susceptible to process errors and environmental temperature variations. The device is insensitive to wavelength fluctuations and does not require a complex wavelength locking mechanism. More importantly, by combining the strong electric field enhancement characteristics of local surface plasmons (enhancement factor of 6.45 × 10³) with the third-order nonlinear effect of transparent conductive oxides in the ENZ band (proportional to the cube of the light intensity), the required pump power can be significantly reduced. Furthermore, the response speed of directly controlling electron concentration is much faster than that of nonlinear effects relying on carrier recombination, thus achieving a modulation speed at the femtosecond level and a significant improvement in modulation depth. In simulations, the extinction ratio of the first branch trench reaches 32.7 dB, and the extinction ratio of the second branch trench reaches 39.1 dB. In addition, the Y-shaped trench and nanomaterial blocks of different thicknesses can be realized through standard photolithography, thermal evaporation, and step-by-step coating processes using a shielding plate, avoiding the complex fabrication process and coupling loss problems of photonic crystals, which is beneficial for low-cost, high-density integration. In summary, this invention has outstanding advantages in terms of low power consumption, high speed, high stability, and ease of fabrication.

[0007] Furthermore, the first and second nano-metal blocks are made of gold, the first nano-metal block has a thickness of 200 nm, and the second nano-metal block has a thickness of 400 nm.

[0008] Furthermore, the substrate is made of glass, the metal waveguide layer has a thickness of 40-50 nm, the metal waveguide layer is made of gold, silver, or aluminum, the transparent conductive oxide is indium tin oxide, the insulating layer is made of silicon dioxide, calcium fluoride, or magnesium fluoride, and the insulating layer has a thickness of 30-50 nm.

[0009] A method for fabricating an all-optical router with low pump power control includes the following steps: Step 1): Select a substrate and clean it. Apply a layer of positive photoresist evenly on the cleaned substrate. Use an electron beam lithography system with a computer to design and draw a Y-shaped waveguide pattern. Expose the photoresist for the first time using electron beam lithography. Perform a first development process on the substrate after the first exposure to obtain a Y-shaped trench photoresist template. Step 2): A layer of metal material is deposited on the surface of the Y-shaped trench photoresist template using a thermal evaporation method. The substrate with the metal material deposited at this time is placed in an acetone solution and gently shaken to remove the positive photoresist, thus obtaining the Y-shaped trench. The Y-shaped trench includes a main trench section and a first branch trench section and a second branch trench section that extend horizontally from the end of the main trench section. Step 3): A layer of transparent conductive oxide is deposited in the Y-shaped trench using a thermal evaporation method to obtain a metal waveguide layer; Step 4): Deposit an insulating layer on the surface of the metal waveguide layer using a thermal evaporation method; Step 5): Apply a layer of positive photoresist evenly to the surface of the insulating layer, design and draw the metal nanostructure pattern using the computer with the electron beam lithography system, and perform a second exposure using the electron beam lithography method. Perform a second development process on the substrate after the second exposure to obtain the metal nanostructure photoresist template. Step 6): A layer of metal material is deposited on the surface of the metal nanostructure photoresist template using a thermal evaporation method. During the deposition process, the areas corresponding to the first branch groove and the second branch groove are blocked with shielding plates respectively. The deposition is carried out in steps so that the two nano metal blocks above the first branch groove and the second branch groove have different thicknesses. Then, the substrate with the metal material deposited at this time is placed in an acetone solution to remove the positive photoresist and obtain the metal nanostructure, thus completing the fabrication of the all-optical router.

[0010] Furthermore, the metal nanostructure includes a first nanometal block and a second nanometal block; the first nanometal block corresponds to the first branch groove segment in the vertical direction, and the second nanometal block corresponds to the second branch groove segment in the vertical direction.

[0011] Furthermore, the substrate is made of glass, the metal waveguide layer has a thickness of 40-50 nm, the metal waveguide layer is made of gold, silver, or aluminum, the insulating layer is made of silicon dioxide, calcium fluoride, or magnesium fluoride, the transparent conductive oxide is indium tin oxide, the insulating layer has a thickness of 30-50 nm, the first and second nano-metal blocks are made of gold, the first nano-metal block has a thickness of 200 nm, and the second nano-metal block has a thickness of 400 nm.

[0012] Furthermore, the positive photoresist is a 200-250 nm thick polymethyl methacrylate.

[0013] An all-optical router with low pump power control is applied in the fields of optical communication, optical sensing, or photoelectric detection. The method is characterized by the following: Pump light is incident on the metal nanostructure, and pump light of different wavelengths selectively excites local surface plasmons of different thicknesses in a first or second nanostructure to generate a local electric field. The generated local electric field modulates the electron concentration distribution of the corresponding branch slot in the metal waveguide layer, changing the absorption loss of the transmitted surface plasmons in that branch slot. This allows for selective output of the surface plasmons from either the first or second branch slot in the Y-shaped trench, achieving all-optical routing control of the surface plasmon transmission path. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram illustrating the implementation of all-optical routing control in Example 1; Figure 3(a) is a schematic diagram of pump light incident on the first and second nano metal blocks based on COMSOL simulation software in Example 1; Figure 3(b) shows the electric field mode distribution when the pump light is incident on the first nano metal block in Example 1; Figure 3(c) is a schematic diagram of transmittance under different pump lights in Example 1; Figure 4(a) is a schematic diagram of the electrostatic field based on COMSOL simulation software in Example 1; Figure 4(b) is a schematic diagram of the changes in electron concentration in indium tin oxide under different electric fields in Example 1; Figure 5(a) is a schematic diagram of the light field based on COMSOL simulation software in Example 1; Figure 5(b) shows the electric field mode distribution in Example 1 without external pump light; Figure 5(c) shows the electric field mode distribution when the electron concentration of the second nano metal block in Example 1 increases; Figure 5(d) shows the electric field mode distribution when the electron concentration of the first nano metal block in Example 1 increases. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0016] Example 1: As Figure 1 As shown, a low-pump optical power controlled all-optical router comprises, from bottom to top, a substrate 1, a metal waveguide layer 21, an insulating layer 3, and a metal nanostructure. The substrate 1 is made of glass. The metal waveguide layer 21 has a thickness of 40 nm and Y-shaped trenches 22 formed therein. The metal waveguide layer 21 is made of gold, and the transparent conductive oxide filled in the Y-shaped trenches 22 is indium tin oxide (ITO). The insulating layer 3 is made of calcium fluoride and has a thickness of 30 nm. The metal nanostructure includes a first nano-metal block 41 and a second nano-metal block 42. The material of the first nano metal block 41 and the second nano metal block 42 is gold. The thickness of the first nano metal block 41 is 200 nm and the thickness of the second nano metal block 42 is 400 nm. The Y-shaped trench 22 includes a main trench section 221 and a first branch trench section 222 and a second branch trench section 223 extending horizontally from the end of the main trench section 221. The first nano metal block 41 is fixedly disposed on the insulating layer 3 at a position corresponding to the first branch trench section 222 in the vertical direction, and the second nano metal block 42 is fixedly disposed on the insulating layer 3 at a position corresponding to the second branch trench section 223 in the vertical direction.

[0017] In this embodiment, the method for manufacturing the all-optical router includes the following steps: Step 1): Select a glass substrate 1 and clean it. Use a spin coater to evenly coat a 200nm thick layer of positive photoresist onto the cleaned substrate 1. Then place it on a heating stage and bake for 2 minutes at a temperature of about 180 degrees Celsius. Dry the positive photoresist. Use the computer-aided design system of the electron beam lithography system to design and draw a Y-shaped waveguide pattern. Perform the first exposure using the electron beam lithography method (i.e., the Y-shaped pattern is not exposed, and the remaining part is fully exposed). Perform the first development treatment on the substrate 1 after the first exposure. Immerse it in the developer for 2 minutes to obtain the Y-shaped trench photoresist template. Step 2): A layer of gold with a thickness of 40nm is deposited on the surface of the Y-shaped trench photoresist template using a thermal evaporation method. The gold-plated substrate 1 is then placed in an acetone solution and heated in a water bath at 40-50 degrees Celsius for 5-10 minutes, while gently shaking to remove the positive photoresist, resulting in a Y-shaped trench 22. The Y-shaped trench 22 includes a main trench section 221 and a first branch trench section 222 and a second branch trench section 223 that extend horizontally from the end of the main trench section 221. Step 3): A layer of indium tin oxide with a thickness of 40 nm is deposited in the Y-shaped trench 22 using a thermal evaporation method to obtain the metal waveguide layer 21; Step 4): A layer of calcium fluoride with a thickness of 30 nm is deposited on the surface of the metal waveguide layer 21 using a thermal evaporation method as an insulating layer 3; Step 5): Use a spin coater to evenly coat a 200nm thick layer of positive photoresist on the surface of the insulating layer 3, then place it on a heating stage and bake for 2 minutes at a temperature of about 180 degrees Celsius. Dry the positive photoresist, use the computer with the electron beam lithography system to design and draw the metal nanostructure pattern, and perform a second exposure using the electron beam lithography method. Perform a second development treatment on the substrate 1 after the second exposure, and soak it in the developer for 2 minutes to obtain the metal nanostructure photoresist template. Step 6): A layer of gold is deposited on the surface of the metal nanostructure photoresist template using a thermal evaporation method. During the deposition process, the areas corresponding to the first branch groove segment 222 and the second branch groove segment 223 are blocked with shielding plates respectively. The deposition is carried out in steps so that the two nano metal blocks above the first branch groove segment 222 and the second branch groove segment 223 have different thicknesses (that is, first cover the area corresponding to the second branch groove segment 223 with a glass plate, deposit a 200nm thick layer of gold on the area corresponding to the first branch groove segment 222 to obtain the first nano metal block 41, then cover the first nano metal block 41 with a glass plate, deposit a 400nm thick layer of gold on the area corresponding to the second branch groove segment 223 to obtain the second nano metal block 42). Then, the substrate 1 with gold at this time is placed in an acetone solution, heated in a water bath at 40-50 degrees Celsius for 5-10 minutes, and gently shaken to remove the positive photoresist, thus obtaining the metal nanostructure and finally completing the fabrication of the all-optical router.

[0018] In this embodiment, the spin coater speed is controlled at around 4000 rpm, and different instruments are set according to the thickness and rotation speed; the thermal evaporation method is to place it in a thermal evaporation coating machine and select a coating rate of 10A / s; the positive photoresist is polymethyl methacrylate (PMMA), and the developer is a mixture of 4-methyl-2-pentanone (MIBK) and isopropanol (IPA) in a 1:3 ratio.

[0019] like Figure 2As shown in this embodiment, the application of this all-optical router in the fields of optical communication, optical sensing, or photoelectric detection is as follows: Pump light is incident on a metal nanostructure, and local surface plasmons of different thicknesses of the first nano metal block 41 or the second nano metal block 42 are selectively excited by pump light of different wavelengths to generate a local electric field. The generated local electric field modulates the electron concentration distribution of the corresponding branch slot in the metal waveguide layer 21, changes the absorption loss of the branch slot for the transmitted surface plasmons, thereby controlling the surface plasmons to be selectively output from the first branch slot 222 (i.e., outlet 2 in the figure) or the second branch slot 223 (i.e., outlet 1 in the figure) in the Y-shaped trench 22, so as to realize all-optical routing control of the surface plasmon transmission path.

[0020] In this embodiment, the all-optical router is 15μm long, 12μm wide, and 8μm high.

[0021] The simulation model of pump light incident on the first nano-metal block 41 (i.e., H1 = 200 nm) and the second nano-metal block 42 (i.e., H2 = 400 nm) is shown in Figure 3(a). As shown in Figure 3(b), when the pump light is incident on the first nano-metal block, the electric field enhancement factor on the surface of the first nano-metal block is 6.45 × 10⁻⁶. 3 As shown in Figure 3(c), H1 is a first nano-metal block 41 with a thickness of 200 nm, and H2 is a second nano-metal block 42 with a thickness of 400 nm. When different wavelengths are incident on the metal nano-blocks of different thicknesses, different structures, i.e., different branches of local surface plasmons, can be selectively excited, which manifest as a transmission peak in the transmission spectrum. Due to the absorption loss of the metal, the light in the corresponding wavelength band is absorbed, resulting in very low transmittance. When the wavelength is 1640 nm, the local surface plasmons of the first nano-metal block 41 can be excited independently, and the extinction ratio of the first branch slot 222 is 32.7 dB. When the wavelength is 1760 nm, the local surface plasmons of the second nano-metal block 42 can be excited independently, and the extinction ratio of the second branch slot 223 is 39.1 dB. They are basically unaffected by each other, which fully demonstrates that the all-optical router of the present invention has the advantages of low crosstalk, high precision, and high performance, and fully meets the stringent requirements of the next-generation all-optical network for routing nodes.

[0022] As shown in Figure 4(a), the Z-axis represents the high position and the X-axis represents the long position. The positive terminal of the external power supply is connected to the first nano-metal block 41 or the second nano-metal block 42, and the negative terminal of the external power supply is connected to the substrate 1. Since the magnitude of the local electric field can be controlled by the incident angle of the pump light (to regulate the excitation efficiency of local surface plasmons), the dynamic control of the change in electron concentration can be achieved. Therefore, the effect of different electric field magnitudes on electron concentration was simulated using an electrostatic field. The electron concentration distribution when the voltage is 3-15V with an interval of 3V is shown in Figure 4(b). Different electric field magnitudes will regulate the electron concentration distribution.

[0023] As shown in Figures 5(a) to 5(d), in the absence of external pump light, plasmon signal light propagates in both the first branch slot 222 and the second branch slot 223 of the Y-shaped trench 22, with the electron concentration set to 1×10². 6 m⁻³; When the electron concentration of the second branch segment 223 increases (at this time, the electron concentration is set to 1×10² for the first branch segment 222). 6 m⁻³, the second branch slot 223 is 4.5×10² 6 When the local surface plasmons of the second nanoscale metal block 42 (m⁻³) are excited, the refractive index of indium tin oxide in its second branch slot 223 increases due to the increase in electron concentration, causing the signal light to be lost and absorbed in the second branch slot 223, resulting in signal light output only in the first branch slot 222; when the electron concentration in the first branch slot 222 increases (at this time, the electron concentration in the first branch slot 222 is set to 3.2 × 10²), the signal light is lost and absorbed in the second branch slot 223, resulting in signal light output only in the first branch slot 222. 6 m⁻³, the second branch slot 223 is 1×10² 6 When the local surface plasmons of the first nano metal block 41 (m⁻³) are excited, the refractive index of indium tin oxide in its first branch slot 222 increases due to the increase in electron concentration, causing the signal light to be lost and absorbed in the first branch slot 222, so that only the second branch slot 223 has signal light output, thereby realizing the function of all-optical routing.

[0024] Example 2: The rest is the same as in Example 1, except that the thickness of the metal waveguide layer 21 is 50nm, the material of the metal waveguide layer 21 is silver, the material of the insulating layer 3 is silicon dioxide, and the thickness of the insulating layer 3 is 40nm. The fabrication method of the all-optical router in this embodiment is basically the same as that in Embodiment 1, except that: in step 2), a layer of silver with a thickness of 50nm is deposited on the surface of the Y-shaped trench photoresist template by thermal evaporation; in step 3), the thickness of indium tin oxide is 50nm; in step 4), a layer of silicon dioxide with a thickness of 40nm is deposited on the surface of the metal waveguide layer 21 by thermal evaporation; in steps 1) and 5), the thickness of the positive photoresist is 150nm; the remaining steps are the same as those in Embodiment 1.

[0025] Example 3: The rest is the same as in Example 1, except that the thickness of the metal waveguide layer 21 is 45nm, the material of the metal waveguide layer 21 is aluminum, the material of the insulating layer 3 is magnesium fluoride, and the thickness of the insulating layer 3 is 50nm. The fabrication method of the all-optical router in this embodiment is basically the same as that in Embodiment 1, except that: in step 2), an aluminum layer with a thickness of 45nm is deposited on the surface of the Y-shaped trench photoresist template using a thermal evaporation method; in step 3), the indium tin oxide layer has a thickness of 45nm; in step 4), a magnesium fluoride layer with a thickness of 50nm is deposited on the surface of the metal waveguide layer 21 using a thermal evaporation method; in steps 1) and 5), the positive photoresist layer has a thickness of 250nm; the remaining steps are the same as those in Embodiment 1.

Claims

1. A low-pump optical power controlled all-optical router, characterized in that... It consists of a substrate, a metal waveguide layer, an insulating layer, and a metal nanostructure arranged in a fixed manner from bottom to top. The metal waveguide layer has Y-shaped trenches filled with transparent conductive oxide. The metal nanostructure includes a first nano-metal block and a second nano-metal block. The Y-shaped trench includes a main trench segment and a first branch trench segment and a second branch trench segment extending horizontally from the end of the main trench segment. The first nano-metal block is fixedly disposed on the insulating layer at a position corresponding to the first branch trench segment in the vertical direction, and the second nano-metal block is fixedly disposed on the insulating layer at a position corresponding to the second branch trench segment in the vertical direction.

2. The all-optical router with low pump optical power control according to claim 1, characterized in that... The first and second nano-metal blocks are made of gold, the first nano-metal block has a thickness of 200 nm, and the second nano-metal block has a thickness of 400 nm.

3. The all-optical router with low pump optical power control according to claim 1, characterized in that... The substrate is made of glass, the metal waveguide layer has a thickness of 40-50 nm, the metal waveguide layer is made of gold, silver or aluminum, the transparent conductive oxide is indium tin oxide, the insulating layer is made of silicon dioxide, calcium fluoride or magnesium fluoride, and the insulating layer has a thickness of 30-50 nm.

4. The method for fabricating a low-pump optical power controlled all-optical router as described in claim 1, characterized in that... Includes the following steps: Step 1): Select a substrate and clean it. Apply a layer of positive photoresist evenly on the cleaned substrate. Use an electron beam lithography system with a computer to design and draw a Y-shaped waveguide pattern. Expose the photoresist for the first time using electron beam lithography. Perform a first development process on the substrate after the first exposure to obtain a Y-shaped trench photoresist template. Step 2): A layer of metal material is deposited on the surface of the Y-shaped trench photoresist template using a thermal evaporation method. The substrate with the metal material deposited at this time is placed in an acetone solution and gently shaken to remove the positive photoresist, thus obtaining the Y-shaped trench. The Y-shaped trench includes a main trench section and a first branch trench section and a second branch trench section that extend horizontally from the end of the main trench section. Step 3): A layer of transparent conductive oxide is deposited in the Y-shaped trench using a thermal evaporation method to obtain a metal waveguide layer; Step 4): Deposit an insulating layer on the surface of the metal waveguide layer using a thermal evaporation method; Step 5): A layer of positive photoresist is uniformly coated on the surface of the insulating layer. A Y-shaped waveguide pattern is designed and drawn using a computer with an electron beam lithography system. The photoresist is exposed a second time using electron beam lithography. The substrate after the second exposure is developed a second time to obtain a metal nanostructure photoresist template. Step 6): A layer of metal material is deposited on the surface of the metal nanostructure photoresist template using a thermal evaporation method. During the deposition process, the areas corresponding to the first branch groove and the second branch groove are blocked with shielding plates respectively. The deposition is carried out in steps so that the two nano metal blocks above the first branch groove and the second branch groove have different thicknesses. Then, the substrate with the metal material deposited at this time is placed in an acetone solution to remove the positive photoresist and obtain the metal nanostructure, thus completing the fabrication of the all-optical router.

5. The method for fabricating an all-optical router with low pump optical power control according to claim 4, characterized in that... The metal nanostructure includes a first nano metal block and a second nano metal block; the first nano metal block corresponds to the first branch groove segment in the vertical direction, and the second nano metal block corresponds to the second branch groove segment in the vertical direction.

6. The method for fabricating an all-optical router with low pump optical power control according to claim 5, characterized in that... The substrate is made of glass, the metal waveguide layer has a thickness of 40-50 nm, the metal waveguide layer is made of gold, silver, or aluminum, the insulating layer is made of silicon dioxide, calcium fluoride, or magnesium fluoride, the transparent conductive oxide is indium tin oxide, the insulating layer has a thickness of 30-50 nm, the first and second nano-metal blocks are made of gold, the first nano-metal block has a thickness of 200 nm, and the second nano-metal block has a thickness of 400 nm.

7. The method for fabricating a low-pump optical power controlled all-optical router according to claim 4, characterized in that... The positive photoresist is a 200-250 nm thick polymethyl methacrylate.

8. The application of the all-optical router with low pump power control as described in claim 1 in the fields of optical communication, optical sensing, or photoelectric detection, characterized in that... The specific method is as follows: Pump light is incident on the metal nanostructure, and local surface plasmons of different thicknesses of the first or second nano metal block are selectively excited by pump light of different wavelengths to generate a local electric field. The generated local electric field modulates the electron concentration distribution of the corresponding branch slot in the metal waveguide layer, changes the absorption loss of the transmitted surface plasmons in the branch slot, thereby controlling the surface plasmons to be selectively output from the first or second branch slot in the Y-shaped trench, and realizing all-optical routing control of the surface plasmon transmission path.

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