First-order mode all-optical switch chip based on polypyrrole nanoparticle array and preparation method thereof

Abstract

The invention provides a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array and a preparation method of the first-order mode all-optical switch chip. The chip comprises a substrate layer, an asymmetric Mach-Zehnder interferometer type waveguide core layer is arranged on the substrate layer, and an upper wrapping layer with the refractive index lower than that of an MZI type waveguide is wrapped outside the waveguide core layer. The invention has the advantages of compact structure and easy integration, and can be widely applied to optical communication networks and optical signal processing systems. Compared with a traditional thermo-optical switch, the all-optical switch chip has the advantages that on the basis of omitting an electrode structure, the preparation method is simple, the response speed is higher, and the power consumption is lower.

Description

Technical Field

[0001] The invention relates to the technical field of optical waveguide type mode optical switches, and in particular to a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array and a preparation method thereof. Background Art

[0002] All-optical switching technology is an important component of all-optical networks and all-optical computing. Traditional electronic switches cannot meet the needs of modern high-speed communications and computing due to the limitation of the speed of electron movement. Photons have the advantages of high frequency and high speed, which makes optical switches have significant advantages in speed and bandwidth. All-optical switching technology directly processes and transmits optical signals, avoiding the loss and delay of photoelectric conversion, improving the efficiency and speed of communication systems, and realizing efficient modulation and control of optical signals. It is of great significance to the realization of high-speed, broadband, and low-power optical communication systems.

[0003] All-optical switching technology has made many advances in various material systems such as silicon photonics, organic photonics, nanophotonics, and plasma structures. Silicon photonics uses silicon as an optical medium and is compatible with existing CMOS processes, making large-scale integration possible. Silicon-based materials achieve all-optical switching through nonlinear optical effects (such as Kerr effect, two-photon absorption, and Raman effect). Its main advantages are efficient optical signal processing capabilities and compatibility with electronic circuits. However, the nonlinear effect of silicon materials is relatively weak, requiring high-power excitation, and there is a problem of optical loss under high-frequency operation. Organic photonic materials, such as organic polymers, have become an important research direction of all-optical switching technology due to their fast optical response time and excellent tunable performance. By adjusting the molecular structure of organic polymers, efficient optical signal processing within a specific wavelength range can be achieved, but compared with silicon materials, polymers have higher optical loss, which affects signal quality. Plasma structures achieve control and modulation of optical signals by exciting plasma waves on the metal surface. The plasma resonance effect confines and enhances light on a subwavelength scale, thereby achieving efficient optical signal processing. However, this method has a complex manufacturing process and high cost. In practical applications, it may face heat dissipation problems. Nanophotonics uses nanoscale structures to control and modulate optical signals. Nanophotonic devices have the characteristics of small size, high speed and low power consumption, which are very suitable for high-density photonic integrated circuits. However, the manufacturing process is complex and the cost is high, requiring precise manufacturing equipment and technology. In recent years, although the introduction of some new materials and technologies has reduced power consumption to a certain extent, in large-scale optical communication networks, especially in dealing with high-speed and high-capacity optical signal processing, how to achieve low-power and high-efficiency all-optical switches is still the key to technological breakthroughs. In addition, with the development of optical information networks and the increase in the demand for information transmission rates, optical switch chips not only require low-power and high-speed information transmission capabilities, but also need to efficiently and quickly allocate optical network resources and build flexible mode division multiplexing systems. Therefore, there is still a lack of technologies that can effectively regulate the propagation path of light in waveguides, realize the conversion and control of fundamental and advanced mode optical signals, and also show low power consumption and fast response in performance. Summary of the invention

[0004] The present invention proposes a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array and a preparation method thereof. The purpose of the present invention is to solve the deficiencies of existing fundamental mode / high-order mode all-optical switch chips in terms of power consumption, response speed and integration. Through innovative structural design and preparation methods, a nanoparticle array is constructed by utilizing the excellent photothermal conversion characteristics of polypyrrole materials to achieve efficient modulation and control of high-order mode optical signals. The chip of the present invention has the advantages of low power consumption, fast response speed, strong stability, etc., and is suitable for mode selection and signal regulation in large-scale, highly integrated optical communication networks.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In order to solve at least one of the above technical problems, according to one aspect of the present invention, the present invention provides a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array, the chip comprising: a substrate layer (100), an asymmetric Mach-Zehnder interferometer type waveguide layer (200) and an upper cladding layer (300) arranged on the substrate layer (100);

[0007] The asymmetric Mach-Zehnder interferometer type waveguide layer (200) comprises: a first polymer core layer (201) and a second polymer core layer (202);

[0008] The internal output end of the asymmetric Mach-Zehnder interferometer waveguide layer (200) is provided with a polypyrrole nanoparticle array (12) for phase modulation, and the asymmetric Mach-Zehnder interferometer waveguide layer (200) is externally coated with an upper cladding layer (300) having a lower refractive index than the asymmetric Mach-Zehnder interferometer waveguide layer (200).

[0009] Preferably, the first polymer core layer (201) comprises a first input straight waveguide (1), a first curved waveguide (3), a first coupling arm (5), a third curved waveguide (7), a first output straight waveguide (9), a third output straight waveguide (11) and a fifth output straight waveguide (14);

[0010] The second polymer core layer (202) is on the first polymer core layer (201), and comprises a second input straight waveguide (2), a second curved waveguide (4), a second coupling arm (6), a fourth curved waveguide (8), a second output straight waveguide (10), a fourth output straight waveguide (13) and a sixth output straight waveguide (15);

[0011] The first input straight waveguide (1) and the second input straight waveguide (2) are arranged in parallel and are respectively connected to the first curved waveguide (3) and the second curved waveguide (4); the first curved waveguide (3) and the second curved waveguide (4) are respectively connected inwardly to a first coupling arm (5) and a second coupling arm (6); the first coupling arm (5) and the second coupling arm (6) are respectively connected to a third curved waveguide (7) and a fourth curved waveguide (8); the ends of the third curved waveguide (7) and the fourth curved waveguide (8) are respectively connected to a first output straight waveguide (9) and a first curved waveguide (10) of the first polymer core layer (201). The second output straight waveguide (10) of the second polymer core layer (201), the first output straight waveguide (9) and the second output straight waveguide (10) are respectively connected to the third output straight waveguide (11) and the fourth output straight waveguide (13), a polypyrrole nanoparticle array (12) is provided between the third output straight waveguide (11) and the fourth output straight waveguide (13), and the third output straight waveguide (11) and the fourth output straight waveguide (13) are respectively connected to the fifth output straight waveguide (14) and the sixth output straight waveguide (15), so as to form a complete asymmetric three-dimensional MZI optical path.

[0012] Preferably, the length L2 of the first curved waveguide (3) and the second curved waveguide (4) in the light transmission direction is consistent, and the length L4 of the third curved waveguide (7) and the fourth curved waveguide (8) in the light transmission direction is consistent; the curved portion of the waveguide adopts a cosine function waveguide form, that is, x = (1-cosπz / L) d, wherein z is the coordinate of the light transmission direction in the waveguide, x is the coordinate of the direction perpendicular to the waveguide, L is the projection of the curved waveguide in the xz direction parallel to the light transmission direction, and d is the projection of the curved waveguide in the xz direction perpendicular to the light transmission direction.

[0013] Preferably, the polypyrrole nanoparticle array (12) is arranged in the middle of the third output straight waveguide (11) of the first polymer core layer (201) and the fourth output straight waveguide (13) of the second polymer core layer (202), and the arrangement and density of the polypyrrole nanoparticle array (12) are controlled to achieve effective modulation of the optical signal; the polypyrrole nanoparticles have a photothermal effect, and when the optical signal passes through, the polypyrrole nanoparticles can absorb light energy and convert it into heat energy, thereby changing the refractive index in the waveguide, thereby achieving modulation of the optical signal.

[0014] Preferably, the pump light excitation wavelength of the polypyrrole nanoparticle array (12) is 0.35-1.4 μm, and the signal light input wavelength is 1.4-1.6 μm. The nanoparticle spacing is 5-500 nm, the particle radius is 5-70 nm, and the particle doping concentration is 0.002-0.5 g / L. The size and spacing of the nanoparticles are optimized to ensure the best photothermal effect and modulation performance at a specific wavelength.

[0015] Preferably, the input pump light and signal light mode is E 00 mode, after being transmitted through the asymmetric MZI waveguide, the pump light mode at the waveguide output is E 00 mode, the signal light mode is converted to E 01 The waveguide structure can achieve E for different input light 00 and E 01 Mode isolation reduces signal light loss and improves the photothermal conversion efficiency of pump light.

[0016] Preferably, the first polymer core layer (201) and the second polymer core layer (202) are made of the same polymer material, such as SU-8 2002, SU-8 2005 or EPO Core. The polymer material has excellent optical properties and processing properties, and can meet the manufacturing requirements of high-precision optical waveguide structures. The material of the upper cladding layer (300) is selected from one of polymethyl methacrylate, polyester or polyimide or EPO Clad.

[0017] Preferably, the input straight waveguide has a thickness of 2 to 20 μm, a width of 1 to 10 μm, and a length of 0.1 to 1 cm;

[0018] The thickness of the curved waveguide and the coupling arm is 1 to 10 μm, the width is 1 to 10 μm, and the length of the coupling arm is 0.5 to 2 cm;

[0019] The output straight waveguide has a thickness of 2 to 20 μm, a width of 1 to 10 μm, and a length of 0.1 to 2.5 cm.

[0020] According to another aspect of the present invention, there is also provided a method for preparing a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array, comprising the following steps:

[0021] S1. Preparation of the first polymer core layer:

[0022] A layer of polymer material is spin-coated on the substrate layer to form a first polymer layer, a waveguide pattern is defined by photolithography technology, and unmasked areas are removed by wet etching to obtain a waveguide pattern.

[0023] S2. Preparation of polypyrrole nanoparticle array buried layer:

[0024] Spin coating a polypyrrole nanoparticle / polymer composite material on the first polymer core layer in step S1 to form a nanoparticle buried layer, and defining the position of the nanoparticle array by a heating and curing technology to obtain a sample containing a polypyrrole nanoparticle array buried layer;

[0025] S3. Preparation of the second polymer core layer:

[0026] In step S2, a layer of polymer material is spin-coated on the sample to form a second polymer core layer, and the second polymer core layer pattern is accurately copied on the first polymer core layer by plate alignment and photolithography technology. In the chip manufacturing process, self-alignment technology is used to ensure the precise alignment of each layer of waveguide structure. The self-alignment technology includes using marking points for alignment, and achieving accurate overlap of each layer of structure through microscope observation and the cooperation of an automatic alignment system to ensure lossless transmission of optical signals in each layer of waveguide; wet etching is used to remove the unmasked area to obtain a waveguide pattern to form a final waveguide structure;

[0027] S4. Preparation of optical waveguide upper cladding:

[0028] Using spin coating technology, a polymer material is spin-coated on the second polymer core layer of the asymmetric MZI type as an upper cladding layer, and then heated and cured to obtain a low-power first-order mode all-optical switch chip based on a polypyrrole nanoparticle array.

[0029] The specific steps of cleaning the substrate layer are as follows:

[0030] Select a clean silicon-based silicon dioxide wafer as the substrate material. In order to ensure the adhesion and quality of the material in the subsequent steps, the substrate needs to be thoroughly cleaned. The specific steps are as follows: First, cut the silicon-based silicon dioxide wafer into 10 to 15 rectangular substrates, soak them in acetone solution, and use an ultrasonic machine to perform ultrasonic cleaning for 15 to 20 minutes. After cleaning, take out the substrate, and then use cotton balls dipped in acetone and ethanol solutions to gently wipe the surface of the substrate, repeatedly to remove the organic matter remaining on the surface. Rinse the substrate with deionized water 2 to 3 times, and blow dry the moisture on the surface of the substrate with nitrogen. Finally, put the cleaned substrate into an oven and bake it at 100 to 120 ° C for 1 to 2 hours to completely remove the moisture on the surface and ensure that it is completely dry.

[0031] The specific steps of spin coating the first layer of polymer material are:

[0032] Use a coating machine to evenly spin-coat a layer of polymer material on the cleaned substrate. During the coating process, pre-coating is first performed for 10 to 30 seconds at a speed of 1000 to 2000 r / min, and then coating is performed for 50 to 100 seconds at a speed of 2000 to 4000 r / min to ensure the formation of a uniform film with a thickness of 1 to 10 μm.

[0033] Pre-baking treatment:

[0034] After spin coating, the sample needs to be pre-baked: place the substrate on a hot plate for heating. The heating process is gradient heating. First, the temperature is 60-90°C for 10-20 minutes, then the temperature is increased to 90-110°C for 30-40 minutes. Finally, turn off the heating plate, and remove the sample after the heating plate temperature has completely cooled to room temperature.

[0035] Lithographically defined waveguide patterns:

[0036] After the first layer of polymer material is spin-coated, the waveguide pattern is defined on it using photolithography. The specific operation is as follows: select a photomask that matches the first layer of polymer waveguide pattern, first place the sample on the photolithography machine, then place the photomask on the sample, and fit the photomask and the sample tightly. Then expose the sample to ultraviolet light for 5 to 20 seconds, with an exposure wavelength of 360 to 370 nm and a light intensity of 20 to 200 mW / cm 2 .

[0037] Post-baking treatment:

[0038] After the exposure is completed, the sample needs to be post-baked: the sample is placed on a hot plate for heating. The heating process is gradient heating. First, the temperature is 60-90°C for 10-20 minutes, and then the temperature is increased to 80-120°C for 30-40 minutes.

[0039] development:

[0040] After the sample is cooled to room temperature, in order to obtain the first layer of polymer waveguide pattern, it needs to be developed: the sample is placed in a developer for 10 to 40 seconds to remove the area not irradiated by ultraviolet light, and finally the desired waveguide pattern is obtained.

[0041] Preparation of polypyrrole nanoparticle array buried layer:

[0042] 0.1-1.5g of polypyrrole nanoparticles are added to 50-100mL of polymer material, stirred at a constant speed for 6-12h on a stirring table at a stirring temperature of 20-40°C, and then the mixed solution is placed in an ultrasonic machine for high-frequency ultrasonic treatment for 16-24h to ensure that the nanoparticles are uniformly dispersed in the polymer. Then the polypyrrole nanoparticles / polymer material is spin-coated on the sample, the spin-coating time is 50-100s, and the speed is 4000-8000r / min. Then, the sample is photolithographed and developed using a matching photomask, the ultraviolet exposure time is 5-20s, and the development time is 10-40s. Finally, the sample is cured at a temperature of 80-120°C and heated for 30-40min to finally obtain a polypyrrole nanoparticle array buried layer.

[0043] Spin coating of the second polymer material:

[0044] A second layer of polymer material is spin-coated on the sample, using the same spin-coating process as the first layer of polymer material to ensure that the thickness of the second layer of polymer is consistent with the thickness of the first layer of polymer.

[0045] Pre-baking treatment:

[0046] After spin coating, the sample was pre-heated and baked using the same heating process as before. The heating process was gradient heating. First, the temperature was set to 60-90°C for 10-20 minutes, and then the temperature was increased to 90-110°C for 30-40 minutes.

[0047] Lithographically defined waveguide patterns:

[0048] After the spin coating of the second layer of polymer material is completed, the waveguide pattern is defined on it using photolithography technology: a photomask matching the second layer of polymer waveguide pattern is selected, the sample is first placed on the photolithography machine, and then the photomask is placed on the sample, and the photomask is tightly attached to the sample. During the production process of the second layer of polymer waveguide, alignment technology is used to ensure the precise alignment of each layer of waveguide structure. The alignment technology includes using marking points for alignment, and through microscope observation and the cooperation of the automatic alignment system, the precise overlap of each layer of structure is achieved to ensure lossless transmission of optical signals in each layer of waveguide. The sample is then exposed to ultraviolet light using the same exposure parameters.

[0049] Post-baking treatment:

[0050] The sample was placed on a hot plate for heating. The heating process was gradient heating. First, the temperature was set to 60-90°C for 10-20 minutes, and then the temperature was raised to 80-120°C for 30-40 minutes.

[0051] development:

[0052] After the sample is cooled to room temperature, it is developed: first, the sample is placed in a developer for 10 to 40 seconds to remove the area not irradiated by the ultraviolet light, and finally a second layer of polymer waveguide patterns is obtained.

[0053] Spin coating cladding material:

[0054] After the final two-layer polymer waveguide pattern is formed, a layer of polymer material is coated on the surface of the sample as an upper cladding layer using spin coating technology to protect the waveguide structure. The rotation speed of the coating machine is controlled at 3000-5000r / min, and the spin coating time is 30-60s to form a uniform upper cladding layer. After the spin coating is completed, the sample is heated and cured for 20-90min at a temperature of 90-150℃ to ensure that the upper cladding layer is completely cured.

[0055] Cleavage end face:

[0056] After the upper cladding is prepared, the sample is cleaved to form a neat optical waveguide end face. The cleavage direction is perpendicular to the transmission direction of light, ensuring that the optical signal can pass through the waveguide structure without loss.

[0057] The chip structure is optimized through finite element analysis (FEA) to ensure the best modulation effect and lowest power consumption under specific light wavelength and power conditions. The finite element multi-physics field analysis includes the light field distribution, thermal field distribution and transient response of the chip structure, and the chip structure is optimized according to the simulation results to ensure the stability and reliability of the chip in practical applications.

[0058] The beneficial effects of the present invention are as follows:

[0059] (1) The present invention utilizes a polypyrrole nanoparticle array structure and can achieve the control function of signal light by introducing pump light. Compared with traditional optical switches, the present invention utilizes the efficient light-to-heat conversion performance of polypyrrole nanoparticles to reduce the switching power consumption of the device.

[0060] (2) The present invention is based on an asymmetric MZI structure. When signal light is input, efficient conversion between the fundamental mode and the first-order mode can be achieved. When pump light is input, fundamental mode input-fundamental mode output can be achieved. Therefore, the fundamental mode and the first-order mode can be isolated for optical signals of different wavelengths. The structure proposed in this project can convert pump light energy into heat energy with maximum efficiency, while also effectively reducing the optical loss of signal light.

[0061] (3) The asymmetric MZI structure proposed in the present invention is compact. Compared with the traditional thermo-optical switch, the all-optical switch chip of the present invention omits the electrode structure, has a simple preparation method, has a high degree of integration, and can achieve good compatibility with existing optoelectronic devices.

[0062] (4) Through the finite element analysis method, the present invention conducts in-depth calculation and simulation of the light-heat-light multi-physical field model, and optimizes the chip structure according to the simulation results, thereby ensuring the stability and reliability of the optical switch chip under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0064] Figure 1 This is a schematic diagram of the structure of a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array in a preferred embodiment of the present invention;

[0065] FIG. 2 is a first-order mode all-optical switch chip (a) based on a polypyrrole nanoparticle array in a preferred embodiment of the present invention. Figure 1 Schematic diagram of the cross section at (a); (b) Figure 1 Schematic diagram of the cross section at (b); (c) Figure 1 Schematic diagram of the cross section at (c);

[0066] Figure 3 It is a process flow chart of preparing a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array in a preferred embodiment of the present invention;

[0067] The meanings of the markings in the figure are as follows: 100 is the substrate layer; 200 is the polymer waveguide layer; 201 is the first polymer core layer; 202 is the second polymer core layer; 300 is the upper cladding layer; 1 is the first polymer core layer as the input straight waveguide; 2 is the second polymer core layer as the input straight waveguide; 3 is the first curved waveguide of the first polymer core layer; 4 is the second curved waveguide of the second polymer core layer; 5 is the first coupling arm of the first polymer core layer; 6 is the second coupling arm of the second polymer core layer; 7 is the third curved waveguide of the first polymer core layer; 8 is the fourth curved waveguide of the second polymer core layer; 9 is the first output straight waveguide of the first polymer core layer; 10 is the second output straight waveguide of the second polymer core layer; 11 is the third output straight waveguide of the first polymer core layer; 12 is the polypyrrole nanoparticle array; 13 is the fourth output straight waveguide of the second polymer core layer; 14 is the fifth output straight waveguide of the first polymer core layer; 15 is the sixth output straight waveguide of the second polymer core layer. DETAILED DESCRIPTION

[0068] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0069] Unless otherwise defined, technical or scientific terms used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs.

[0070] The following is combined with Figure 1-3 The specific embodiments of the present invention are described in detail with examples.

[0071] Example 1

[0072] According to the instruction manual Figure 1As shown in FIG. 2 , the present invention provides a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array. The chip includes a substrate layer 100 and an asymmetric MZI structure waveguide layer 200 disposed on the substrate layer 100. The waveguide layer 200 is composed of a first polymer core layer 201 and a second polymer core layer 202. A polypyrrole nanoparticle array 12 for phase modulation is disposed at the output end of the waveguide layer 200. The outer portion of the waveguide layer 200 is coated with an upper cladding layer 300 having a lower refractive index than the core layer.

[0073] The asymmetric MZI polymer waveguide structure 200, wherein the first polymer core layer 201 includes a first input straight waveguide 1, a first curved waveguide 3, a first coupling arm 5, a second curved waveguide 7, a first output straight waveguide 9, a third output straight waveguide 11 and a fifth output straight waveguide 14. The second polymer core layer 202 is located on the first polymer core layer 201, and includes an input straight waveguide 2, a first curved waveguide 4, a second coupling arm 6, a fourth curved waveguide 8, a second output straight waveguide 10, a fourth output straight waveguide 13 and a sixth output straight waveguide 15. The first input straight waveguide 1 in the first polymer core layer 201 and the second input straight waveguide 2 in the second polymer core layer 202 are arranged in parallel, and the first input straight waveguide 1 and the second input straight waveguide 2 are connected to the first curved waveguide 3 and the second curved waveguide 4, respectively. The lengths of the first curved waveguide 3 and the second curved waveguide 4 in the light transmission direction (z direction) are consistent, and the lengths L4 of the third curved waveguide 7 and the fourth curved waveguide 8 in the light transmission direction (z direction) are consistent. The first curved waveguide 3 and the second curved waveguide 4 are connected inwardly, and are connected to the first coupling arm 5 and the second coupling arm 6 respectively. The first coupling arm 5 and the second coupling arm 6 are further connected to the third curved waveguide 7 and the fourth curved waveguide 8 respectively. The curved part of the waveguide adopts the cosine function waveguide form, that is, x=(1-cosπz / L)·d, where z is the coordinate of the light transmission direction in the waveguide, x is the coordinate of the perpendicular waveguide direction, L is the projection of the curved waveguide in the xz direction parallel to the light transmission direction, and d is the projection of the curved waveguide in the xz direction perpendicular to the light transmission direction. The ends of the curved waveguides 7 and 8 are connected to the first output straight waveguide 9 and the second output straight waveguide 10 respectively, and the first output straight waveguide 9 and the second output straight waveguide 10 are connected to the third output straight waveguide 11 and the fourth output straight waveguide 13 respectively, and a polypyrrole nanoparticle array 12 is provided between the third output straight waveguide 11 and the fourth output straight waveguide 13. Finally, the ends of the third output straight waveguide 11 and the fourth output straight waveguide 13 are connected to the fifth output straight waveguide 14 and the sixth output straight waveguide 15 respectively, forming a double-layer asymmetric MZI waveguide structure.

[0074] As an optional solution, the asymmetric MZI type first polymer core layer 201 and the second polymer core layer material 202 of this embodiment are selected from SU-8 2002, the substrate material 100 is selected from silicon-based silicon dioxide, and the upper cladding material 300 is selected from polymethyl methacrylate.

[0075] As an optional solution, the thickness of the substrate layer in this embodiment is 0.8 mm, the thickness of the input waveguide and the output straight waveguide of the asymmetric MZI waveguide 200 is 10 μm, and the thickness h5 of the upper cladding layer is 5 μm.

[0076] Further, the thickness h3 of the first polymer core layer 201 and the thickness h4 of the second polymer core layer 202 are the same, wherein the thickness of the first curved waveguides 3 and 4, the first coupling arm 5, the second coupling arm 6, and the second curved waveguides 7 and 8 is 5 μm.

[0077] Furthermore, the nanoparticle spacing in the polypyrrole nanoparticle array layer is 200 nm, the particle radius is 40 nm, and the particle doping concentration is 0.4 g / L. The pump light excitation wavelength is 1.31 μm, and the signal light input wavelength is 1.55 μm.

[0078] Further, the width w3=w4 of the input straight waveguides 1 and 2 of the asymmetric MZI waveguide 200 is 5 μm, and the length L1 is 0.2 cm. The length L2 of the first curved waveguide 3 and the second curved waveguide 4 is 2000 μm, wherein the distance d1 from the first polymer core layer 201 to the center of the waveguide is 5 μm, and the distance d2 from the second polymer core layer 202 to the center of the waveguide is 22.5 μm. The length L2 of the first coupling arm 5 and the second coupling arm 6 is 2000 μm, wherein the distance d3 from the first polymer core layer 201 to the center of the waveguide is 5 μm, and the distance d4 from the second polymer core layer 202 to the center of the waveguide is 22.5 μm. The length L5 of the first output straight waveguides 9 and 10 is 3000 μm, the length L6 of the third output straight waveguide 11 and the fourth output straight waveguide 13 is 10000 μm, and the length L6 of the fifth output straight waveguide 14 and the sixth output straight waveguide 15 is 5000 μm.

[0079] Example 2

[0080] As attached Figure 3 As shown, a method for preparing a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array comprises the following steps:

[0081] S1. Preparation of the first polymer core layer

[0082] (1) Cleaning of the substrate: Select a clean silicon-based silica wafer as the substrate material. First, cut the silicon-based silica wafer into 10 to 15 rectangular substrates, soak them in acetone solution, and use an ultrasonic machine to perform ultrasonic cleaning for 20 minutes. After cleaning, take out the substrate, and then use a cotton ball dipped in acetone and ethanol solution to gently wipe the surface of the substrate, repeatedly to remove the organic matter remaining on the surface. Rinse the substrate with deionized water 3 times and blow dry the moisture on the surface of the substrate with nitrogen. Finally, put the cleaned substrate into an oven and bake it at 120°C for 2 hours to completely remove the moisture on the surface and ensure that it is completely dry.

[0083] (2) Spin coating the first layer of polymer material: Use a coating machine to evenly spin coat a layer of polymer material on the cleaned substrate, including two processes: pre-coating and coating. After the spin coating is completed, the sample needs to be pre-baked to form a uniform polymer film.

[0084] As an optional solution, the pre-spinning time in this embodiment is 15 seconds, the rotation speed is 2000 r / min, and the spinning time is 50 seconds, the rotation speed is 3000 r / min, so as to ensure the formation of a uniform film with a thickness of 5 μm.

[0085] Furthermore, the pre-baking process is a gradient heating process, first the temperature is 60°C, heated for 10 minutes, then the temperature is increased to 95°C, heated for 20 minutes. Finally, the heating plate is turned off, and the sample can be removed after the temperature of the heating plate is completely cooled to room temperature.

[0086] (3) Photolithography defines the waveguide pattern: Select a photomask that matches the first layer of polymer waveguide pattern. First, place the sample on the photolithography machine, then place the photomask on the sample, fit the photomask tightly against the sample, and then expose the sample to ultraviolet light. After the exposure is completed, the sample needs to be post-baked.

[0087] As an optional solution, the UV exposure time is 8s, the exposure wavelength is 3608nm and the light intensity is 100mW / cm 2 The post-baking temperature is 60°C for 10 minutes, and then the temperature is increased to 95°C for 20 minutes.

[0088] (4) After the sample is cooled to room temperature, in order to obtain the first layer of polymer waveguide pattern, it needs to be developed. The sample is placed in a developer for 13 seconds to remove the area not irradiated by ultraviolet light, and finally the desired polymer waveguide pattern is obtained.

[0089] S2. Preparation of polypyrrole nanoparticle array buried layer

[0090] (1) 0.5 g of polypyrrole nanoparticles were added to 50 mL of polymer material and stirred at a constant speed on a stirring table for 12 h at a stirring temperature of 30 °C. The mixture was then placed in an ultrasonic machine for high-frequency ultrasonic treatment for 24 h to ensure that the nanoparticles were evenly dispersed in the polymer.

[0091] (2) Spin-coating the polypyrrole nanoparticle / polymer material onto the sample described in S1, and then pre-baking the sample to form a uniform polypyrrole nanoparticle / polymer film.

[0092] As an optional solution, the pre-sizing time in this embodiment is 15s, the speed is 2000r / min, the sizing time is 60s, the speed is 5000r / min, the pre-baking process temperature is 95°C, and the heating is 30min. Finally, turn off the heating plate, and remove the sample after the temperature of the heating plate is completely cooled to room temperature.

[0093] (3) The sample was subjected to photolithography and development, with the UV exposure time being 8 seconds and the development time being 13 seconds. Finally, the sample was subjected to curing treatment at a temperature of 120° C. for 30 minutes, and finally a polypyrrole nanoparticle array buried layer 12 was obtained.

[0094] S3. Preparation of the Second Polymer Core Layer

[0095] (1) A second layer of polymer material is spin-coated on the sample in step S2. After the spin coating is completed, the sample is heated and pre-baked to form a second layer of polymer film.

[0096] Preferably, the same spin coating process and heating process as in S1 are used to ensure that the thickness of the second polymer layer is consistent with the thickness of the first polymer layer.

[0097] (2) Photolithography to define the waveguide pattern: After the spin coating of the second layer of polymer material is completed, the waveguide pattern is defined on it using photolithography technology. A photomask that matches the second layer of polymer waveguide pattern is selected. The sample is first placed on the photolithography machine, and then the photomask is placed on the sample, and the photomask is tightly attached to the sample. During the production process of the second layer of polymer waveguide, alignment technology is used to ensure the precise alignment of each layer of waveguide structure. The alignment technology includes using marking points for alignment, and through microscope observation and the cooperation of the automatic alignment system, the precise overlap of each layer of structure is achieved to ensure lossless transmission of optical signals in each layer of waveguide. The sample is then subjected to UV exposure and post-baking.

[0098] Preferably, the same exposure parameters as in S1 are used, with the post-baking heating temperature being 60° C. for 10 min and 95° C. for 20 min.

[0099] (3) Development: The sample is placed in a developer and developed to obtain a second layer of polymer waveguide pattern. Preferably, the same development parameters as in S1 are used.

[0100] S4. Upper cladding preparation

[0101] (1) After the two-layer polymer waveguide pattern is formed, a layer of polymer material is coated on the surface of the sample by spin coating technology as an upper cladding layer. After the spin coating is completed, the sample is heated and cured to protect the waveguide structure.

[0102] As an optional solution, the rotation speed of the coating machine in this embodiment is controlled at 3000 r / min, the spin coating time is 40 s, and a uniform upper cladding layer is formed. The heating time is 30 min, and the temperature is 120°C.

[0103] (2) After the upper cladding layer is prepared, the sample is cleaved to ensure a neat optical waveguide end face. The cleavage direction should be perpendicular to the light transmission path to ensure that the optical signal can pass through the waveguide structure without loss.

[0104] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A first-order mode all-optical switch chip based on polypyrrole nanoparticle array, characterized in that: The chip comprises: a substrate layer (100), an asymmetric Mach-Zehnder interferometer type waveguide layer (200) and an upper cladding layer (300) arranged on the substrate layer (100); The asymmetric Mach-Zehnder interferometer type waveguide layer (200) comprises: a first polymer core layer (201) and a second polymer core layer (202); The internal output end of the asymmetric Mach-Zehnder interferometer waveguide layer (200) is provided with a polypyrrole nanoparticle array (12) for phase modulation, and the outside of the asymmetric Mach-Zehnder interferometer waveguide layer (200) is coated with an upper cladding layer (300) having a lower refractive index than the asymmetric Mach-Zehnder interferometer waveguide layer (200).

2. The first-order mode all-optical switch chip based on polypyrrole nanoparticle array according to claim 1, characterized in that: The first polymer core layer (201) comprises a first input straight waveguide (1), a first curved waveguide (3), a first coupling arm (5), a third curved waveguide (7), a first output straight waveguide (9), a third output straight waveguide (11) and a fifth output straight waveguide (14); The second polymer core layer (202) is on the first polymer core layer (201), and comprises a second input straight waveguide (2), a second curved waveguide (4), a second coupling arm (6), a fourth curved waveguide (8), a second output straight waveguide (10), a fourth output straight waveguide (13), and a sixth output straight waveguide (15); The first input straight waveguide (1) and the second input straight waveguide (2) are arranged in parallel and are respectively connected to the first curved waveguide (3) and the second curved waveguide (4); the first curved waveguide (3) and the second curved waveguide (4) are respectively connected inwardly to a first coupling arm (5) and a second coupling arm (6); the first coupling arm (5) and the second coupling arm (6) are respectively connected to a third curved waveguide (7) and a fourth curved waveguide (8); the ends of the third curved waveguide (7) and the fourth curved waveguide (8) are respectively connected to the first output straight waveguide (9) and the first output straight waveguide (9) of the first polymer core layer (201). The second output straight waveguide (10) of the second polymer core layer (201) is connected to the third output straight waveguide (11) and the fourth output straight waveguide (13) respectively. A polypyrrole nanoparticle array (12) is provided between the third output straight waveguide (11) and the fourth output straight waveguide (13). The third output straight waveguide (11) and the fourth output straight waveguide (13) are connected to the fifth output straight waveguide (14) and the sixth output straight waveguide (15) respectively, thereby forming a complete asymmetric three-dimensional MZI optical path.

3. The first-order mode all-optical switch chip based on polypyrrole nanoparticle array according to claim 2, characterized in that: The length L2 of the first curved waveguide (3) and the second curved waveguide (4) in the light transmission direction is consistent, and the length L4 of the third curved waveguide (7) and the fourth curved waveguide (8) in the light transmission direction is consistent; the curved portion of the waveguide adopts a cosine function waveguide form, that is, x=(1-cosπz / L)·d, wherein z is the coordinate of the light transmission direction in the waveguide, x is the coordinate of the direction perpendicular to the waveguide, L is the projection of the curved waveguide in the xz direction parallel to the light transmission direction, and d is the projection of the curved waveguide in the xz direction perpendicular to the light transmission direction.

4. The first-order mode all-optical switch chip based on polypyrrole nanoparticle array according to any one of claim 3, characterized in that: The polypyrrole nanoparticle array (12) is arranged in the middle of the third output straight waveguide (11) of the first polymer core layer (201) and the fourth output straight waveguide (13) of the second polymer core layer (202). By controlling the arrangement and density of the polypyrrole nanoparticle array (12), effective modulation of the optical signal is achieved; the polypyrrole nanoparticles have a photothermal effect. When the optical signal passes through, the polypyrrole nanoparticles can absorb light energy and convert it into heat energy, changing the refractive index in the waveguide, thereby achieving modulation of the optical signal.

5. The first-order mode all-optical switch chip based on polypyrrole nanoparticle array according to claim 4, characterized in that: The pump light excitation wavelength of the polypyrrole nanoparticle array (12) is 0.35 to 1.4 μm, and the signal light input wavelength is 1.4 to 1.6 μm. The nanoparticle spacing is 5 to 500 nm, the particle radius is 5 to 70 nm, and the particle doping concentration is 0.002 to 0.5 g / L. The size and spacing of the nanoparticles are optimized to ensure optimal photothermal effect and modulation performance at a specific wavelength.

6. The first-order mode all-optical switch chip based on polypyrrole nanoparticle array according to claim 5, characterized in that: The input pump light and signal light mode is E 00 mode, transmitted through the asymmetric MZI waveguide, the pump light mode at the waveguide output is E 00 Mode, signal light mode is converted to E 01 mode. This waveguide structure can achieve E for different input light 00 and E 01 Mode isolation reduces signal light loss and improves the photothermal conversion efficiency of pump light.

7. The first-order mode all-optical switch chip based on polypyrrole nanoparticle array as claimed in claim 1, characterized in that: The first polymer core layer (201) and the second polymer core layer (202) are made of the same polymer material, such as SU-82002, SU-8 2005, or EPO Core. The polymer material has excellent optical properties and processing properties, and can meet the manufacturing requirements of high-precision optical waveguide structures. The material of the upper cladding layer (300) is selected from one of polymethyl methacrylate, polyester, polyimide, or EPO Clad.

8. The first-order mode all-optical switch chip based on polypyrrole nanoparticle array according to claim 2, characterized in that: The input straight waveguide has a thickness of 2 to 20 μm, a width of 1 to 10 μm, and a length of 0.1 to 1 cm; The thickness of the curved waveguide and the coupling arm is 1 to 10 μm, the width is 1 to 10 μm, and the length of the coupling arm is 0.5 to 2 cm; The output straight waveguide has a thickness of 2 to 20 μm, a width of 1 to 10 μm, and a length of 0.1 to 2.5 cm.

9. A method for preparing a first-order mode all-optical switch chip based on a polypyrrole nanoparticle array, characterized in that: The steps include: S1. Preparation of the first polymer core layer: A polymer material is spin-coated on the substrate layer to form a first polymer layer, a waveguide pattern is defined by photolithography, and an unmasked area is removed by wet etching to obtain a waveguide pattern; S2. Preparation of buried layer of polypyrrole nanoparticle array: Spin-coating a polypyrrole nanoparticle / polymer composite material on the first polymer core layer in step S1 to form a nanoparticle buried layer, and defining the position of the nanoparticle array by a heat curing technique to obtain a sample containing a polypyrrole nanoparticle array buried layer; S3. Preparation of the second polymer core layer: In step S2, a layer of polymer material is spin-coated on the sample to form a second polymer core layer. The second polymer core layer pattern is accurately replicated on the first polymer core layer through plate alignment and photolithography technology. During the chip manufacturing process, self-alignment technology is used to ensure the precise alignment of each layer of the waveguide structure. The self-alignment technology includes using marking points for alignment, and through microscopic observation and the cooperation of an automatic alignment system, the precise overlap of each layer of the structure is achieved, ensuring lossless transmission of optical signals in each layer of the waveguide; removing the unmasked area by wet etching to obtain a waveguide pattern, thereby forming a final waveguide structure; S4. Preparation of optical waveguide upper cladding: Using spin coating technology, a polymer material is spin-coated on the second polymer core layer of the asymmetric MZI type as the upper cladding layer, and then heated and cured to obtain a low-power first-order mode all-optical switch chip based on a polypyrrole nanoparticle array.

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