A preparation method of a high-quality-factor chalcogenide photonic crystal flat plate on a chip

Abstract

The application belongs to the technical field of crystal flat preparation, and particularly relates to a preparation method of a high-quality-factor chalcogenide photonic crystal flat on a chip, which comprises the following steps: S1. Chalcogenide film is thermally evaporated on a silicon-based substrate, and the chalcogenide film sample is composed of a chalcogenide film layer, a silicon dioxide lower cladding layer and a silicon substrate from top to bottom; S2. Photoresist is spin-coated on the upper surface of the chalcogenide film sample; after dry etching, physical degumming and water bath sol, high-quality-factor photonic crystal panel preparation is further realized through thermal annealing. Based on the non-volatile photorefraction characteristics of chalcogenide materials, the chalcogenide photonic crystal panel prepared through band gap light irradiation can realize dynamic regulation and control of resonant light in the panel; the application can obtain resonant modes with super-high Q value while simplifying the device structure, can break through the limitation of mode design of photonic crystals under the light cone, and can realize resonant lossless continuous tuning through the photorefraction effect of the chalcogenide film.

Description

Technical Field

[0001] The present invention belongs to the technical field of crystal slab preparation, and in particular relates to a method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab. Background Art

[0002] Since their introduction in 1987, photonic crystals have been widely used in physics and communications due to their flexible manipulation of light and strong binding capabilities. Photonic crystal microcavities, in particular, have attracted widespread attention in high-density optical communications, high-precision optical measurement, high-power laser sources, and multifunctional on-chip devices due to their higher quality factors and smaller mode volumes. However, the design of traditional photonic crystal resonators relies heavily on the optical band gap, which is further limited by the band structure and light line, and is also very complex to manufacture.

[0003] Most photonic crystal devices are statically responsive. Currently, the few photonic crystals that can achieve dynamic tunability primarily rely on thermo-optical tuning, carrier tuning, and phase-change material tuning. However, these methods introduce additional losses, limiting further device development. The photorefractive properties of chalcogenide glasses (ChGs) demonstrate the tunability of chalcogenide optical devices without introducing losses, providing insights and specific solutions for the fabrication of tunable and reconfigurable photonic crystal devices.

[0004] However, existing photonic crystal devices still have the following problems:

[0005] 1. The processing precision of photonic crystals is high. The defect cavity of photonic crystals, especially the nanometer-scale aperture near the resonant cavity, requires very precise parameters, which puts high demands on the processing and preparation. In actual processing, the device quality is often affected by the shortcomings of etching and degumming processes.

[0006] 2. Currently, photonic crystal devices usually respond statically. It is difficult for a photonic crystal resonator to meet multiple resonant frequencies. At the same time, it is also limited by the light cone in the energy band. The frequencies above the light cone cannot be completely confined in the photonic crystal. Some dynamic tuning schemes such as thermo-optical tuning and carrier tuning will introduce additional device losses.

[0007] 3. Photonic crystal resonators for nonlinear effects are more difficult to realize. Currently, the Q value of general photonic crystals is around 1000, which greatly limits nonlinear applications;

[0008] 4. The general tuning methods of tunable photonic crystals include thermo-optic tuning, carrier tuning, phase change material tuning, etc., which will introduce additional losses and reduce the quality factor of the device resonance. Summary of the Invention

[0009] The purpose of the present invention is to provide a method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab, which can obtain a resonant mode with an ultra-high Q value while simplifying the device structure, and can break through the limitations of the mode design of the photonic crystal below the light cone, and realize the simultaneous excitation of multiple high-Q resonant modes above the light cone.

[0010] The technical solutions adopted by the present invention are as follows:

[0011] A method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab, the method comprising the following steps:

[0012] S1. Thermally evaporate a chalcogenide thin film onto a silicon substrate. From top to bottom, the chalcogenide thin film sample consists of a chalcogenide thin film layer, a silicon dioxide lower cladding layer, and a silicon substrate.

[0013] S2. Spin-coating a photoresist on the upper surface of the chalcogenide film sample;

[0014] S3. Electron beam exposure;

[0015] S4. Reactive Ion Etching: A reactive ion beam etching system was used to perform ion bombardment and reactive ion etching on the chalcogenide thin film sample containing the photoresist pattern layer. Argon, tetrafluoromethane, and trifluoromethane were selected as etching gases for the chalcogenide material.

[0016] After etching is completed, photonic crystal holes with uniform depth and size, smooth sidewalls and high verticality, as well as residual photoresist patterns are formed in the chalcogenide thin film layer;

[0017] S5. Water bath stripping: Use an organic solvent to heat a water bath to dissolve the remaining photoresist, and then blow dry to obtain the photonic crystal holes with a trace amount of residual resist.

[0018] S6. Blue Film Removal: Using adhesive tape, we remove trace amounts of residual adhesive from the surface of photonic crystal holes with diameters of 400nm-500nm, resulting in a large-area, high-quality factor chalcogenide photonic crystal slab.

[0019] S7. Annealing: After the desmearing is completed, annealing is performed at 300°C for more than 10 hours in a vacuum or inert gas environment to further reduce the surface roughness of the photonic crystal slab and obtain a large-area, high-quality factor chalcogenide photonic crystal slab.

[0020] S8. Reconfigurable dynamic tuning of resonant modes: Utilizing the photorefractive effect of chalcogenide materials, a bandgap laser is used to irradiate and pump a photonic crystal slab, changing the material's refractive index and shifting the resonant mode frequency of the photonic crystal, achieving dynamic tunability while maintaining a high Q value during the tuning process.

[0021] In S1, the method for processing the chalcogenide thin film sample further includes the following steps:

[0022] S11. Charging: First, in an inert gas glove box, crush the prepared high-purity chalcogenide material glass into fine particles using a knocker. Then, place the evaporation boat on an electronic balance and slowly add a small amount of particles using a spatula. Finally, remove the evaporation boat from the glove box and install it in the coating machine.

[0023] S12. Substrate pretreatment: First, perform wet ultrasonic cleaning on the substrate outside the coating machine. Then, place the silicon-based substrate into the coating machine and perform radio frequency cleaning on the substrate using argon ions.

[0024] S13. Evaporation process: Set the evaporation temperature range to 520℃-540℃, perform a pre-evaporation process to fully melt the sulfide material and stabilize the evaporation, then open the upper baffle and perform formal coating to obtain a sulfide thin film sample with a target thickness of 850nm-1000nm.

[0025] In S3, the electron beam exposure comprises the following steps:

[0026] S31. First, use K-Layout software to draw the exposure layout;

[0027] S32. Then, the exposed pattern is processed autonomously using the electron beam exposure software. Enter the optimized parameters: exposure resolution 0.001-0.01nm, step size 10-30nm, dose 100-350uC / cm 2 , beam current 5-8na; then send the sample into the exposure chamber, run the program for exposure, and form the target photoresist pattern layer;

[0028] S33. Finally, remove the sample and use the photoresist developer solution to remove the electron beam glue in the exposed area. Then fix the photoresist with the solution and wash away the developer solution. If the development is incomplete when observed under a microscope, the above process needs to be optimized again.

[0029] The spin coating of the photoresist in S2 comprises the following steps:

[0030] S21. Pretreatment: First, ultrasonically clean the sulfide film sample and then dry it on a hot plate to remove excess moisture.

[0031] S22. Coating: Then, a photoresist is spin-coated on the surface of the chalcogenide film sample;

[0032] S23. Soft baking: Finally, place the sample on a hot plate and soft bake the coated photoresist at 130°C for 5 minutes to cure it, and then cool it down.

[0033] The solution used in wet ultrasonic cleaning is any one of acetone, ethanol and deionized water.

[0034] The solution used in the ultrasonic cleaning in the pre-treatment of spin coating photoresist is any one of acetone, isopropyl alcohol and deionized water.

[0035] The organic solvent used in the water bath stripping is any one of NMP (N-methyl pyrrolidone) and DMSO (dimethyl sulfoxide).

[0036] The adhesive tape film used in the blue film stripping is any one of a silicon wafer blue film, a mechanical peeling special blue film and stationery glue.

[0037] The dynamic tuning in the S8 is tuning using a bandgap light to irradiate a photonic crystal flat plate;

[0038] A bandgap laser with a wavelength of 532 nm is used as a pump source to irradiate the photonic crystal flat plate, and the laser power density on the surface of the flat plate is 200-800 mW / cm 2 After each pumping for 30 seconds, the laser is turned off and the resonance shift is recorded to obtain fine tuning with a step of 0.08-0.1 nm, and reducing the pumping power or reducing the irradiation time can reduce the compensation and improve the fineness of the tuning.

[0039] The annealing process in the S7 further includes the following steps:

[0040] A. 3 hours to make the annealing furnace temperature rise to 300 DEG C;

[0041] B. Keep the annealing temperature at 300 DEG C for 10-20 hours;

[0042] C. 10 hours from 300 DEG C to room temperature.

[0043] The technical effects obtained by the present application are:

[0044] The preparation method of the on-chip high-quality factor chalcogenide photonic crystal flat plate of the present application uses the design idea of continuous domain bound state (BIC), which can simplify the device structure, obtain a resonant mode with ultra-high Q value, break through the limitation of mode design under the light cone of the photonic crystal, realize simultaneous excitation of multiple high-Q resonant modes above the light cone, and further realize its application in the fields of laser, sensing, nonlinearity, etc.

[0045] The device design parameters of the preparation method of the on-chip high-quality factor chalcogenide photonic crystal flat plate of the present application have robustness, and different apertures and periods can realize high-quality factor resonance, greatly simplifying the accuracy requirements for design and processing.

[0046] The preparation method of the on-chip high-quality factor chalcogenide photonic crystal flat plate of the present application adopts the scheme of water bath plus blue film adhesion in the stripping process, avoiding the problems including material oxidation deformation, residual photoresist around the hole, etc. caused by the traditional oxygen stripping scheme. The large-area photonic crystal flat plate is completely stripped, and the surface reflectivity is improved.

[0047] The preparation method of the on-chip high-quality factor chalcogenide photonic crystal flat plate has dynamic tunability and reconfigurable characteristics. The photonic crystal flat plate is irradiated with a bandgap light, which can finely tune the resonance frequency while maintaining the Q value of the resonance mode. Compared with other tunable photonic crystals, the advantages are that no additional loss is introduced, the tuning method is simple, and the resonance frequency can be reset through device post-processing methods such as annealing, realizing reconfiguration. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 is a process flow chart of an embodiment of the present application;

[0049] Figure 2 is a schematic diagram of high-Q BIC resonance of a photonic crystal structure in an embodiment of the present application;

[0050] Figure 3 is a structural schematic diagram of a large-area chalcogenide photonic crystal flat plate in an embodiment of the present application;

[0051] Figure 4 is a schematic diagram of the resonance tuning test optical path in an embodiment of the present application;

[0052] Figure 5 is a statistical diagram of the resonance frequency movement in the tuning process of an embodiment of the present application;

[0053] Figure 6 is a schematic diagram of the quality factor remaining unchanged in the tuning process of an embodiment of the present application.

[0054] In the drawings, the components represented by each reference numeral are listed as follows:

[0055] 1, first process; 2, second process; 3, third process; 4, fourth process; 5, fifth process; 6, sixth process; 7, silica lower cladding layer; 8, silicon substrate; 9, silicon-based substrate; 10, chalcogenide thin film layer; 11, chalcogenide thin film sample; 12, photoresist; 13, photoresist pattern layer; 14, photonic crystal hole; 15, photoresist pattern; 16, organic solvent; 17, trace residual glue; 18, adhesive tape film. DETAILED DESCRIPTION

[0056] In order to make the purpose and advantages of the present application clearer and more apparent, the present application will be specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present application, and does not strictly limit the specific protection scope requested by the present application.

[0057] As Figures 1-6As shown, a preparation method of a high-quality factor chalcogenide photonic crystal flat plate on a chip is provided, which realizes a reconfigurable high-quality factor chalcogenide photonic crystal flat plate while keeping the Q value unchanged; the hole structure photonic crystal flat plate with smooth side walls and high verticality can be prepared by the provided technology, lossless resonance frequency tuning within a certain range can be realized, and the Q value remains unchanged; the preparation method comprises the following steps:

[0058] S1. A high-adhesion and uniform chalcogenide thin film is thermally evaporated on a silicon-based substrate 9, and the chalcogenide thin film sample 11 is composed of the chalcogenide thin film layer 10, the lower silica cladding layer 7 and the silicon substrate 8 from top to bottom;(see the first process 1 in the drawing)

[0059] The thin film layer 10 is a chalcogenide photonic material with photorefractive properties, and any one of arsenic sulfide (As2S3) thin film, arsenic selenide (As2Se3) thin film, germanium arsenic selenide (Ge-AsSe) thin film, germanium arsenic sulfide (Ge-As-S) thin film, germanium antimony selenide (Ge-Sb-Se) thin film, germanium antimony sulfide (Ge-Sb-S) and arsenic sulfide selenide (AsS-Se) thin film is adopted.

[0060] Photorefractive refers to the phenomenon that the physical properties of a material change reversibly after being irradiated by light, which is mainly caused by light-induced structural phase change; by utilizing the photorefractive properties of the material, the physical state of the material is changed under light irradiation to realize information writing, reading and erasing, thereby realizing data storage and retrieval; the photorefractive material can be used to prepare light-controlled photonic crystals and photonic chips. By adjusting the light, the lattice structure and optical properties of the photorefractive material can be changed, thereby realizing the tuning of the photonic crystal and the function switching of the photonic chip, and the photorefractive material is widely used in the fields of optical sensing, photonic devices and photonic integrated circuits.

[0061] In S1, the processing mode of the chalcogenide thin film sample 11 further comprises the following steps:

[0062] S11. Filling: first, in a glove box containing inert gas, the prepared high-purity chalcogenide material bulk glass is knocked into fine particles with a knocking rod, then a small amount of particles is slowly added into an evaporation boat with a medicine spoon, and finally the evaporation boat is taken out of the glove box and installed in the inside of a film coating machine;

[0063] S12. Substrate pretreatment: first, the substrate is cleaned by wet ultrasonic cleaning outside the film coating machine, and then the silicon-based substrate 9 is put into the film coating machine and cleaned by radio frequency cleaning with argon ions;

[0064] Specifically, the solution used in the wet ultrasonic cleaning is any one of acetone, ethanol and deionized water;

[0065] Acetone has good solubility, which can effectively dissolve and remove some oil, dirt and organic matter. It can quickly disperse and suspend oil and dirt in the solution, so that the ultrasonic wave can better clean and remove the dirt on the surface of the object;

[0066] Ethanol is a common solvent, which can effectively remove stains and residues in wet ultrasonic cleaning, especially for water-soluble stains and some organic matter. It has good stain removal performance and can dissolve and remove many difficult-to-clean substances;

[0067] Deionized water is obtained by removing ions and impurities in it through special deionization equipment. The use of deionized water in ultrasonic cleaning can ensure that there is no ion residue and water stain on the surface of the cleaned object, reducing the stains and marks after cleaning.

[0068] S13. Evaporation process: set the evaporation temperature range to 520-540℃, perform pre-evaporation process to make the chalcogenide material fully melt, and then open the upper baffle to perform formal film plating to obtain high-quality chalcogenide thin film sample 11 with a target thickness of 850-1000 nm.

[0069] S2. Spin coating photoresist 12 on the upper surface of the above-mentioned chalcogenide thin film sample 11; (see Figure 2 for details)

[0070] S21. Pretreatment: first, ultrasonic cleaning of the chalcogenide thin film sample 11, then drying the excess water with a hot plate;

[0071] S22. Gluing: then spin coating photoresist 12 on the upper surface of the chalcogenide thin film sample 11;

[0072] S23. Soft baking: finally, place the sample on a hot plate to perform soft baking and curing of the coated photoresist 12 at 130℃ for 5 minutes, and then cool down;

[0073] S3. Electron beam exposure;

[0074] In S3, the electron beam exposure includes the following steps:

[0075] S31. First, use the software K-Layout to draw the exposure layout;

[0076] S32. Then, use the electron beam exposure related software to independently process the exposed pattern, input the optimized parameters: exposure resolution 0.001-0.01 nm, step 10-30 nm, dose 100-350 uC / cm 2 , beam current 5-8 na; then send the sample into the exposure room and run the program to expose, forming the target photoresist pattern layer 13; (see Figure 3 for details)

[0077] S33. Finally, the sample is removed, the exposed areas of the electron beam resist are removed using a developer solution for the photoresist, the photoresist is then fixed using a solution, and the developer solution is washed away. If the development is not complete under a microscope, the above process needs to be optimized again.

[0078] S4. Reactive ion etching: The sample of the chalcogenide thin film containing the photoresist pattern layer is subjected to ion bombardment and reactive ion etching using a reactive ion beam etching system, and argon (Ar), tetrafluoromethane (CF4) and trifluoromethane (CHF3) are selected as etching gases for the chalcogenide material;

[0079] After etching, the photonic crystal hole 14 with uniform depth and size, smooth side wall and high verticality is formed in the chalcogenide thin film layer 10, and the residual photoresist pattern 15 is also formed.(See Figure 4 for details)

[0080] S5. Water bath stripping: The residual photoresist is dissolved by heating the water bath with organic solvent 16, and the photonic crystal hole 14 with a small amount of residual glue 17 is obtained after drying.(See Figure 5 for details)

[0081] In the water bath stripping process, NMP (N-methyl pyrrolidone) or DMSO (dimethyl sulfoxide) is used as the organic solvent 16.

[0082] Specifically, using NMP (N-methyl pyrrolidone) or DMSO (dimethyl sulfoxide) as the organic solvent 16 has the following advantages:

[0083] Dissolve the adhesive: NMP and DMSO have good solubility and can effectively dissolve and remove various types of adhesives. They can penetrate and disperse in the adhesive, causing it to dissolve, so that the adhesive loses its viscosity, making it easy to clean and remove;

[0084] Softening the adhesive: NMP and DMSO can also soften the adhesive. After contacting with the adhesive, they can change its physical properties, making it soft, easy to handle and remove. The softened adhesive can be more easily removed by cleaning agents and tools, improving the effectiveness and efficiency of the stripping process;

[0085] Dissolve and remove residues: NMP and DMSO can also effectively dissolve and remove adhesive residues during the stripping process. They can penetrate into the adhesive residues, causing them to dissolve or disperse, thereby helping to remove the residues and maintain a clean surface.

[0086] S6. Blue film stripping: The small amount of residual glue 17 on the surface of the photonic crystal hole 14 with a diameter of 400-500 nm is removed by using an adhesive tape film 18, and a large-area, high-quality factor chalcogenide photonic crystal flat plate is obtained.(See Figure 6 for details)

[0087] Among them, the adhesive tape film 18 used in the blue film adhesive removal is any one of a silicon wafer blue film, a mechanical peeling special blue film, and stationery glue;

[0088] Specifically, the silicon wafer blue film, the mechanical peeling special blue film, and the stationery glue have the following effects:

[0089] Silicon wafer blue film: The silicon wafer blue film is a high-temperature resistant blue adhesive tape commonly used in the semiconductor industry and electronic manufacturing process. It has strong adhesion and high-temperature resistance, can effectively adhere to the surface, and protect the surface from damage and contamination. In the blue film adhesive removal process, the silicon wafer blue film can be used as a protective layer to prevent adhesive residues and other contaminants from adhering to the substrate, facilitating cleaning and disposal;

[0090] Mechanical peeling special blue film: The mechanical peeling special blue film is a specially designed adhesive tape with high peel strength and tensile strength. It is widely used in material separation and removal processes, can effectively adhere to adhesive residues, and can be separated and removed by mechanical peeling. The mechanical peeling special blue film plays a role in bearing and helping to peel in the blue film adhesive removal process, effectively removing adhesive residues and purifying the surface;

[0091] Stationery glue: Stationery glue is a common adhesive with certain adhesion and adhesion. In the blue film adhesive removal process, stationery glue can be used as an auxiliary tool to help remove the silicon wafer blue film and the mechanical peeling special blue film. Stationery glue can be attached to the adhesive film to form a tearable glue ball, thereby helping to peel and remove the blue film together.

[0092] S7. Annealing: After adhesive removal, annealing is performed at 300℃ for more than 10 hours in a vacuum or inert gas environment to further reduce the surface roughness of the photonic crystal flat panel and obtain a large-area, high-quality factor sulfur photonic crystal flat panel;

[0093] The annealing process in S7 further includes the following steps:

[0094] A. 3 hours to raise the temperature in the annealing furnace to 300℃;

[0095] B. Maintain the 300℃ annealing temperature for 10-20 hours;

[0096] C. 10 hours from 300℃ to room temperature.

[0097] S8. Reconfigurable resonant mode dynamic tuning: using the photorefraction effect of chalcogenide material, the photonic crystal slab is irradiated by bandgap laser, the refractive index of the material is changed, so that the resonant mode frequency of the photonic crystal is moved, dynamic tuning is realized, and high Q value is maintained during tuning, without introducing additional loss. In addition, the frequency of the resonant mode can be reset by post-processing methods such as device annealing (300-350℃), to realize reconfiguration.

[0098] The dynamic tuning in S8 is to use bandgap light to irradiate the photonic crystal slab for tuning;

[0099] A bandgap laser with a wavelength of 532nm is used as a pump source to irradiate the photonic crystal slab, and the laser power density on the surface of the slab is 200-800mW / cm 2 After each pump of 30 seconds, the laser is turned off and the resonance shift is recorded, which obtains a fine tuning step of 0.08-0.1nm, and reducing the pump power or irradiation time can reduce the compensation and improve the tuning accuracy.

[0100] During the tuning process, the quality factor of the resonant mode remains unchanged (see attached figure Figure 6 After tuning, the photonic crystal slab can be annealed by the same annealing process parameters (S7), and after completion, the frequency of the resonant mode can be reset, and the quality factor remains unchanged.

[0101] During the irradiation and pumping process of the photonic crystal slab, a laser that meets the material bandgap wavelength is used, which can be a continuous light laser or a pulsed light laser.

[0102] Specifically, the continuous light laser emits continuous light beams, which can be used for continuous irradiation on the photonic crystal slab. The photonic crystal is an optical structure composed of periodic medium arrangement, which can interact with light under the irradiation of the continuous light laser. The continuous light laser can provide a stable light source for the research and application of the photonic crystal slab in a continuous state, such as photonic crystal sensors, photonic crystal filters, etc.

[0103] The pulsed light laser emits high-intensity, short-time-domain light pulses, which can be used for irradiation of the photonic crystal slab in a very short time. The photonic crystal can generate complex optical phenomena through nonlinear effects under the action of the pulsed light laser, such as nonlinear light transmission, dynamic grating formation, etc. The pulsed light laser has the characteristics of providing high energy and short pulse width light beams, which is suitable for nonlinear optical research and application of the photonic crystal slab.

[0104] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application. The structures, devices and operation methods not specifically described and explained in the present application are implemented according to the conventional means in the art, unless specifically described and limited.

Claims

1. A method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab, characterized by: The preparation method comprises the following steps: S1. Thermally evaporate a chalcogenide thin film onto a silicon substrate. From top to bottom, the chalcogenide thin film sample consists of a chalcogenide thin film layer, a silicon dioxide lower cladding layer, and a silicon substrate. S2. Spin-coating a photoresist on the upper surface of the chalcogenide film sample; S3. After pre-treatment, coating and soft baking, electron beam exposure is performed; S4. Reactive Ion Etching: A reactive ion beam etching system was used to perform ion bombardment and reactive ion etching on the chalcogenide thin film sample containing the photoresist pattern layer. Argon, tetrafluoromethane, and trifluoromethane were selected as etching gases for the chalcogenide material. After etching is completed, photonic crystal holes with uniform depth and size, smooth sidewalls and high verticality, as well as residual photoresist patterns are formed in the chalcogenide thin film layer; S5. Water bath stripping: Use an organic solvent to heat a water bath to dissolve the remaining photoresist, and then blow dry to obtain photonic crystal holes with a trace amount of residual resist. S6. Blue film removal: Use adhesive tape to remove trace amounts of residual adhesive from the surface of photonic crystal holes with a diameter of 400nm-500nm; S7. Annealing: After the desmearing is completed, annealing is performed above the glass transition temperature in a vacuum or inert gas environment for more than 10 hours to further reduce the surface roughness of the photonic crystal slab and obtain a large-area, high-quality factor chalcogenide photonic crystal slab; S8. Reconfigurable dynamic tuning of resonant modes: Utilizing the photorefractive effect of chalcogenide materials, a bandgap laser is used to irradiate and pump a photonic crystal slab, changing the material's refractive index and shifting the resonant mode frequency of the photonic crystal, achieving dynamic tunability while maintaining a high Q value during the tuning process.

2. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 1, characterized in that: In S1, the method for processing the chalcogenide thin film sample further includes the following steps: S11. Charging: First, in an inert gas glove box, crush the prepared high-purity chalcogenide material glass into fine particles using a knocker. Then, place the evaporation boat on an electronic balance and slowly add a small amount of particles using a spatula. Finally, remove the evaporation boat from the glove box and install it in the coating machine. S12. Substrate pretreatment: First, perform wet ultrasonic cleaning on the substrate outside the coating machine. Then, place the silicon-based substrate into the coating machine and perform radio frequency cleaning on the substrate using argon ions. S13. Evaporation process: Set the evaporation temperature range to 520℃-540℃, perform a pre-evaporation process to fully melt the sulfide material and stabilize the evaporation, then open the upper baffle and perform formal coating to obtain a sulfide thin film sample with a target thickness of 850nm-1000nm.

3. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 1, characterized in that: In S3, the electron beam exposure comprises the following steps: S31. First, use K-Layout software to draw the exposure layout; S32. Then, the exposed pattern is processed autonomously using the electron beam exposure software. Enter the optimized parameters: exposure resolution 0.001-0.01nm, step size 10-30nm, dose 100-350uC / cm 2 , beam current 5-8na; then send the sample into the exposure chamber, run the program for exposure, and form the target photoresist pattern layer; S33. Finally, remove the sample and use the photoresist developer solution to remove the electron beam glue in the exposed area. Then fix the photoresist with the solution and wash away the developer solution. If the development is incomplete when observed under a microscope, the above process needs to be optimized again.

4. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 1, characterized in that: The spin coating of the photoresist in S2 comprises the following steps: S21. Pretreatment: First, ultrasonically clean the sulfide film sample and then dry it on a hot plate to remove excess moisture. S22. Coating: Then, a photoresist is spin-coated on the surface of the chalcogenide film sample; S23. Soft baking: Finally, place the sample on a hot plate and soft bake the coated photoresist at 130°C for 5 minutes to cure it, and then cool it down.

5. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 4, characterized in that: The solution used for ultrasonic cleaning in the pre-treatment of the spin-coated photoresist in S21 is any one of acetone, isopropyl alcohol and deionized water.

6. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 2, characterized in that: The solution used in the wet ultrasonic cleaning in S12 is any one of acetone, ethanol and deionized water.

7. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 1, characterized in that: The organic solvent in the water bath degumming is any one of NMP (N-methylpyrrolidone) and DMSO (dimethyl sulfoxide).

8. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 1, characterized in that: The adhesive tape film used in blue film removal can be any one of silicon wafer blue film, mechanical peeling special blue film, and stationery glue.

9. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 1, characterized in that: The dynamic tuning in S8 is performed by irradiating the photonic crystal slab with bandgap light; A bandgap laser with a wavelength of 532 nm is used as a pump source to irradiate the photonic crystal slab. The laser power density on the slab surface is 200-800 mW / cm 2 After each pumping for 30 seconds, the laser was turned off and the resonance shift was recorded to obtain fine tuning with a step size of 0.08-0.1nm. Reducing the pump power or shortening the irradiation time can reduce the compensation and improve the fineness of the tuning.

10. The method for preparing an on-chip high-quality factor chalcogenide photonic crystal slab according to claim 1, characterized in that: The annealing temperature in S7 is determined according to the glass transition temperature of the deposited chalcogenide thin film.

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