Nano-imprinting-based micro-nano array resonant cavity nano laser chip preparation method

Abstract

The invention provides a nano-imprinting-based micro-nano array resonant cavity nano laser chip preparation method, belongs to the technical field of miniaturized lasers, solves the problems of high cost, long time and small preparation area of a traditional template preparation method, and comprises the following steps: step 1, preparing a single-pass AAO hole array template through an anodic oxidation method; 2, carrying out chemical etching on the single-pass AAO hole array template, and preparing a double-pass AAO template adhered to ITO (Indium Tin Oxide); 3, performing physical vapor deposition on the bi-pass AAO template adhered to the ITO to obtain a metal plasmon resonant cavity required by the nano laser device; and 4, forming a plasmon nano laser based on the metal plasmon resonant cavity and the gain material, and preparing a nano laser chip.

Description

Technical Field

[0001] The invention relates to a method for preparing a micro-nano array resonant cavity nano laser chip based on nano-imprinting, and belongs to the technical field of miniaturized lasers. Background Art

[0002] The first key component of nanoimprint technology is a hard nano mold with a fine concave-convex structure on its surface. The mold is like a template, used to shape the target material. During the nanoimprint process, the hard mold is accurately pressed into the aluminum foil material. At this time, it is crucial to accurately control the parameters of temperature and pressure. Only under the appropriate time and pressure can the aluminum foil material be deformed under the action of the concave-convex structure of the mold and produce thickness differences.

[0003] In natural environment conditions, a dense aluminum oxide film with a thickness of 2nm is usually formed on the surface of metallic aluminum. This dense and stable aluminum oxide layer can effectively prevent further oxidation of the internal metal. A thicker aluminum oxide layer than the natural oxide layer can be prepared by electrochemical methods. Since metallic aluminum is used as an anode material during the oxidation process, this preparation method is called anodic oxidation. The difference in its electrolyte will lead to differences in the morphology of anodized aluminum oxide, such as non-porous barrier type and porous type. The pore size and pore spacing of porous AAO can be regulated by the selection of anodizing conditions. This polymorphic AAO structure has laid the foundation for the development of functional nanodevices with its controllable structural characteristics. With the demand for miniaturization and integration of devices, porous AAO has been widely used in the preparation of optical microcavities, nanostructured materials and nanofunctional devices with its advantages of parameter controllability, low preparation cost, diverse preparation methods and the ability to prepare ordered arrays in large areas at the centimeter level.

[0004] The mode volume of the plasmonic nanostructure is very small, and the near field will be greatly enhanced at the resonant frequency, which makes it widely used in the research of nanolasers. In general, a plasmonic nanolaser consists of a plasmonic nanocavity and a gain material. Using the nanoscale cavity as optical feedback, it can be transferred from the gain material to the plasmon resonant mode. The excitation of the nanolaser can be achieved when the following two conditions are met: one is that the spectrum between the plasmonic nanostructure and the gain material overlaps, and resonance can be generated in the spatial position; the other is that the pump energy reaches the threshold. The threshold is proportional to the loss of the nanocavity rate. Therefore, the main difficulty in developing plasmonic nanolasers is to develop low-loss nanocavities. Summary of the invention

[0005] The present invention solves the problems of high cost, long time and small preparation area of ​​the traditional template preparation method, and further proposes a method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: the present invention comprises the following steps:

[0007] Step 1: Prepare a single-pass AAO pore array template by anodization method;

[0008] Step 2: chemically etching the single-pass AAO hole array template to prepare a double-pass AAO template adhered to ITO;

[0009] Step 3: Physical vapor deposition is performed on the double-pass AAO template adhered to ITO to obtain the metal plasmon resonant cavity required for the nano-laser device;

[0010] Step 4: Based on the metal plasmon resonant cavity and gain material, a plasmon nanolaser is constructed to prepare a nanolaser chip.

[0011] Preferably, step 1 specifically includes:

[0012] Step 1.1: Cut the aluminum sheet into discs with a diameter of 2 cm, immerse the cut aluminum sheet in ultrapure water and clean it with ultrasound, take out the aluminum sheet after ultrasonic cleaning for 10 minutes, immerse it in ethanol and clean it with ultrasound, and after ultrasonic cleaning for 10 minutes, obtain the aluminum sheet after impurities are removed;

[0013] Step 1.2: prepare a polishing agent from a mixture of perchloric acid and ethanol, place the polishing agent on a magnetic stirrer to make it flow, place a lead plate on the cathode of the magnetic stirrer, place an aluminum sheet on the anode of the magnetic stirrer, set the parameters of the magnetic stirrer and turn on the magnetic stirrer to allow the lead plate and the aluminum sheet to react in an ice water bath for 4 to 6 minutes, remove the rough surface of the aluminum sheet, and then use ultrapure water and ethanol to ultrasonically clean it again for 5 minutes in sequence;

[0014] Step 1.3: Select a nickel film with a square period of 400nm as a template, use a sheet press to imprint the preset pattern on the surface of the aluminum sheet after ultrasonic cleaning, prepare an oxidizing solution, and use the oxidizing solution to anodize the imprinted aluminum sheet to obtain a single-pass AAO hole array template with a square period of 400nm.

[0015] Preferably, in step 1.2, the volume ratio of perchloric acid to ethanol is 1:7, and the parameters of the magnetic stirrer include: the reaction voltage is set to 30V, the reaction current is set to 2A / piece, and AAO is anodized aluminum.

[0016] Preferably, in step 1.3, the pressure of the tablet press is 5 MPa, the imprinting time is 2 mins, the oxidizing solution consists of phosphoric acid, ethylene glycol and water, the volume ratio of phosphoric acid, ethylene glycol and water is 1:200:400, the anodizing environment is: constant voltage is 160 V, current is 0.015 A / piece, and oxidation time is 60 mins.

[0017] Preferably, step 2 specifically includes:

[0018] Step 2.1: Use a spin coater to spin-coat the PMMA solution on the surface of the single-pass AAO hole array template, and cure it in a 30°C oven for 1 hour to protect the AAO surface and support the template. Place the cured single-pass AAO hole array template in a cupric chloride solution for a replacement reaction, so that the aluminum substrate at the bottom of the single-pass AAO hole array template corrodes and peels off, obtaining an AAO hole array template with a PMMA protective layer on the front side;

[0019] Step 2.2: Fix the AAO hole array template with a PMMA protective layer on the front side and the back side facing upward on a glass slide and immerse it in a phosphoric acid aqueous solution. Chemically etch the AAO film barrier layer for a preset time in a water bath at 55°C to obtain a square hole template. Remove the square hole AAO template from the glass slide and immerse it in analytical grade acetone to remove the attached PMMA. Use ITO to pick up the film and dry it. After the acetone is completely evaporated, the AAO template adhered to ITO is obtained, wherein ITO is a conductive glass.

[0020] Preferably, the PMMA solution in step 2.1 is 1 g PMMA + 20 mL analytically pure CH 2 Cl 2 The mixed solution has a curing time of 1 h, and the mass fraction of the phosphoric acid aqueous solution in step 2.2 is 5%.

[0021] Preferably, step 3 specifically includes:

[0022] The metal target material is evaporated on a double-pass AAO template adhered to ITO by physical vapor deposition. The metal vapor passes through the through holes of the double-pass AAO template and adheres to the ITO substrate to form a metal dot array. After the template is removed using a low-viscosity electrostatic tape, a uniformly distributed square metal nanoparticle array is obtained on the ITO surface, completing the preparation of the metal plasmon resonant cavity required for the nanolaser device.

[0023] Preferably, step 4 specifically includes:

[0024] The gain material is dissolved in anhydrous ethanol of analytical purity at a ratio of 1 mg:1 mL, and the gain material dissolved in anhydrous ethanol is injected into a groove consisting of two thin cover glasses bonded with UV-curing glue, and the square metal nanoparticle array on the ITO surface is placed in the groove and immersed in the gain material for compounding, wherein the gain material is Nile red.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention combines nanoimprint technology and anodization technology to design the template, and then uses physical vapor deposition technology to design the metal plasmon resonant cavity, and selects a matching gain medium to realize the preparation of a miniaturized nano-laser. Compared with the existing physical preparation template method, the production cost is greatly reduced, and the size of the nano-laser can be adjusted and the preparation can be repeated.

[0027] 2. The present invention introduces nanoimprint technology to achieve adjustable area of ​​pre-fabricated patterns and high preparation repeatability; then introduces an anodic aluminum oxide chemical growth method to obtain a single-hole structure with uniform growth depth and morphology; finally, a chemical etching method is used to etch the single-hole structure into a double-hole structure. Because the chemical etching solution uses an immersion method to react, the uniformity and size controllability of the obtained double-hole structure can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A flow chart of the method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting provided by the present invention;

[0029] Figure 2 This is a SEM image of a square single-pass AAO template array provided by the present invention. Figure 2 In the figure, (a) is a top view of a square single-pass AAO template array, and (b) is a side view of a square single-pass AAO template array;

[0030] Figure 3 This is the SEM image of the single-pass square AAO template provided by the present invention before and after hole expansion. Figure 3 In the figure, (a) is a schematic diagram of the back morphology of AAO before hole expansion, and (b) is a schematic diagram of the back morphology of AAO with a square hole obtained after hole expansion;

[0031] Figure 4 This is a schematic diagram of metal plating of a double-pass square AAO template provided by the present invention. Figure 4 In the figure, (a) is a schematic diagram of the 3D model of the square AAO template coated with metal, and (b) is a SEN diagram of the square AAO template coated with metal;

[0032] Figure 5 A schematic diagram of the transmission dispersion spectrum of Ag-Squ-NPs provided by the present invention;

[0033] Figure 6 A schematic diagram of the nano-laser radiation system provided by the present invention, Figure 6 In the figure, (a) is a schematic diagram of a nano-laser radiation system from a top view, (b) is a schematic diagram of a nano-laser radiation system from a side view, and (c) is a schematic diagram of a nano-laser radiation system in reality;

[0034] Figure 7 A schematic diagram of the laser test optical path provided by the present invention;

[0035] Figure 8 This is a schematic diagram of the laser test optical path test results provided by the present invention, Figure 8 In the figure, (a) is a schematic diagram of the sample emission spectrum changing with the pump intensity, and (b) is a schematic diagram of the curve of the Nile Red-Ag NPs emission light intensity and half-maximum full width changing with the pump intensity;

[0036] Fig. 9 A schematic diagram of the polarization of the emitted light of Ag-Squ-NPs provided by the present invention;

[0037] Fig.10 This is a schematic diagram of the laser emission spectrum provided by the present invention changing with time. DETAILED DESCRIPTION

[0038] Specific implementation method 1: Combination Figure 1-6 To illustrate this embodiment, Figure 1 As shown, the steps of the method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting described in this embodiment include:

[0039] S1: Preparation of single-pass AAO pore array template by anodization method;

[0040] S101: Preparation: Cut the aluminum sheet into discs with a diameter of 2 cm, and then immerse it in ultrapure water and clean it with ultrasound for 10 minutes; then take out the aluminum sheet and immerse it in ethanol and clean it with ultrasound for 10 minutes to remove impurities attached to the surface of the aluminum sheet to achieve a cleaning effect;

[0041] S102: Electrochemical polishing: Prepare a polishing agent with a mixture of perchloric acid and ethanol in a volume ratio of 1:7, and place it on a magnetic stirrer to make the polishing agent flow. Place a lead plate on the cathode, and an aluminum sheet on the anode. Set the reaction voltage to 30V, and the reaction current to 2A / sheet. Power on in an ice water bath for 4 to 6 minutes to remove the rough surface of the aluminum sheet, and finally obtain a smooth and flat aluminum sheet. After the reaction is completed, use ultrapure water and ethanol to ultrasonically clean it again, and dry it for use;

[0042] S103: Imprint oxidation: Use a square nickel film with a period of 400nm as a template, and use a sheet press (pressure 5MPa, time 2mins) to press the preset pattern onto the surface of the aluminum sheet. After imprinting, the imprinted area with structural color can be seen by the naked eye, and then anodization is performed. The oxidation liquid ratio is phosphoric acid: ethylene glycol: water = 1:200:400, at a constant voltage of 160V, a current of 0.015A / sheet, and an oxidation time of 60mins. After oxidation, the following can be obtained: Figure 2(a) shows a large-area square 400nm periodic single-pass AAO hole array template. At this time, AAO is attached to an aluminum substrate. In order to obtain the AAO template, S2 is required to peel off the aluminum substrate.

[0043] S2: chemically etching the single-pass AAO hole array template to prepare a double-pass AAO template adhered to ITO;

[0044] S201: Aluminum stripping: Before aluminum stripping, use a spin coater to spin-coat the PMMA solution on the sample surface. The PMMA solution consists of 1g PMMA + 20mL analytically pure CH 2 Cl 2 The AAO template is then cured in an oven at 30°C for 1 hour to protect the AAO surface and support the template. The sample obtained in the third step is placed in a copper chloride solution. Since aluminum and copper chloride will undergo a replacement reaction, while aluminum oxide does not react with copper chloride, the aluminum substrate at the bottom can be gradually corroded and peeled off without damaging the AAO template. Finally, an AAO hole array template with a PMMA protective layer on the front is obtained. Figure 2 (a) and Figure 2 In the scanning electron microscope (SEM) image shown in (b), the morphology of the square AAO hole array can be seen.

[0045] S202: Chemical pore expansion and transfer: The AAO film with PMMA attached is fixed on a glass slide with the back side facing upward, immersed in a 5% phosphoric acid aqueous solution, and the barrier layer of the AAO film is chemically etched for a certain period of time in a water bath at 55°C to obtain a square hole template. The sample is then removed from the glass slide and immersed in analytically pure acetone to remove the attached PMMA. The film is picked up and dried using conductive glass (ITO) to completely evaporate the acetone to obtain a double-pass AAO template attached to ITO, such as Figure 3 As shown in (a) and (b).

[0046] S3: Physical vapor deposition is performed on the double-pass AAO template adhered to ITO to obtain the metal plasmon resonant cavity required for the nano-laser device;

[0047] This embodiment uses physical vapor deposition technology to evaporate the metal target on the AAO template. Since the template has a double through-hole structure, the metal vapor passes through the through-holes and adheres to the ITO substrate to form a metal dot array.

[0048] After the template is removed using low-viscosity electrostatic tape, the purpose of using low-viscosity electrostatic tape is to prevent the tape from removing the metal array, so that a uniformly distributed metal array is obtained on the ITO surface. The shape of the metal array here is limited by the shape of the template through-holes. Since the template is placed with the square holes on the back facing upward, a square metal nanoparticle array can be obtained, that is, the metal plasmon resonant cavity required for the nano-laser device. The schematic diagram of the 3D model of the square AAO template metal plating (taking silver as an example) is shown in the figure. Figure 4 As shown in (a), the SEM image of the square AAO template plated with metal (taking silver as an example) is as follows Figure 4 (b) as shown.

[0049] S4: Prepare nanolaser chips based on plasmon nanolasers composed of metal plasmon resonators and gain materials.

[0050] like Figure 6 As shown, the metal nanoarray on ITO is compounded with luminescent dye molecules, and Nile Red is selected as the dye molecule. The compounding method is immersion compounding, that is, Nile Red is dissolved in anhydrous ethanol with a purity specification of analytical grade at a ratio of 1 mg: 1 mL, and the mixture is injected into a groove composed of two thin cover glass slides bonded with ultraviolet curing glue, and then the metal nanoarray on ITO is placed in the groove, and the structural part is completely immersed in the dye, so as to prepare a nano laser radiation system of metal nanoparticles compounded with Nile Red.

[0051] Figure 5 The left figure shows the dispersion relation of a square lattice metal (silver as an example) nanoparticle array (Ag-Squ-NPs) array with a height of 140nm when the incident light azimuth angle is 0° when the refractive index is matched with anhydrous ethanol (the ambient refractive index is 1.37), where the black dashed line depicts DOs, and the right figure describes the transmission spectrum of Ag-Squ-NPs at 0° and the luminescence spectrum of NileRed dye. By in-depth analysis of the transmission dispersion diagram (the transmission intensity value of the scale bar is the transmitted light intensity I t / Incident light intensity I in ), this embodiment finds that the degenerate DOs are / / = 0, the group velocity approaches zero, which leads to the formation of band edge modes and prolongs the interaction time between the incident light and the array. The photon energy of the degenerate state is 1.93 eV, which overlaps with the emission spectrum of Nile red, enabling the array to provide effective optical feedback to the dye. When the light is obliquely incident along the Γ-X path (k / / ≠0), (0, 1) and (0, -1) two-photon states remain degenerate, but the two-photon states of (1,0) and (-1,0) move to the high-energy and low-energy branches, respectively. In this case, the local state density decreases and the group velocity increases. The transmission spectrum can be analyzed to show a sharp SLRs resonance peak at 640nm, which overlaps with the emission spectrum of Nile Red. SLRs can provide optical feedback to the gain medium.

[0052] Specific implementation method 2: Combination Figure 7-10 This embodiment is described. In order to better verify the modulation effect of the square metal nanoparticle array in the specific embodiment, this embodiment uses a 267fs, 515nm pulsed laser to excite a square metal (taking silver as an example) nanoparticle array composite Nile Red device (Nile Red-Ag-Squ-NPs) at room temperature and collects the emission spectrum in the 0° emission direction. Figure 7 The laser optical path of the test is shown. A femtosecond laser light source is used as the pump light. It is focused on the sample through a converging lens to emit a nano-laser perpendicular to the sample surface. The laser signal is received by the spectrometer through the signal receiving optical path. The inset is an actual photo of the laser output spot with a diameter of about 1 mm. The azimuth angle of the array relative to the incident laser is 0°.

[0053] Through the above tests, the present embodiment found that: (1) at a lower pump intensity (<14.80 mJ / cm 2 ), only a low intensity amplified spontaneous emission (full width at half maximum (fwhm) ∼50 nm) is collected at the receiving end. This is caused by two reasons. The first one is caused by the Nile Red molecules and is independent of the angle. Since the molecules are spatially far away from the nanoparticles (and outside the SLRs mode volume), they do not emit into the SLRs mode. The second one is caused by the periodic distribution of the metal particles. (2) At the critical pump intensity (∼14.80 mJ / cm 2 ), a sharp and strong emission peak (λ=640nm, fwhm=13nm) was collected at the receiving end, and the emission peak position basically matched the SLRs peak position of Ag-Squ-NPs transmission spectrum. (3) As the pump power exceeded the threshold (>14.80mJ / cm 2 ), the emission peak intensity continued to increase and then stabilized at 4×10 4 The fwhm decreases to ~10 nm and then remains stable. The transition from spontaneous emission to lasing is manifested by a sudden change in the emission spectrum, such as Figure 8 (a) shown.

[0054] like Figure 8 (b) summarizes the variation of emission intensity and linewidth with increasing pump energy. It is worth noting that if the pump energy density is increased from 12.10 mJ / cm2 Increased to 14.80mJ / cm 2 , the emission intensity measured in this embodiment ranges from ~2×10 3 to 1.5×10 4 At the same time, the line width of the emission peak decreases from ~50nm to 13nm, which indicates that in this pump intensity range, the optical feedback intensity of the array to the gain medium surges, thereby obtaining laser emission.

[0055] Fig. 9 Nile Red-Ag-Squ-NPs at a pump energy of 17.83 mJ / cm 2 Polar coordinate diagram of the emission intensity changing with the polarization state. At polarization angles of 0° and 90°, the output laser of Nile Red-Ag-Squ-NPs has strong elliptical coherent emission, which is related to the symmetry of the square lattice.

[0056] Fig.10 Describes the change of laser emission over time, when the pump energy is maintained at 17.83mJ / cm 2 In this case, as time goes by, the remaining amount of gain medium gradually decreases as the laser continues to work, resulting in a gradual decrease in laser output intensity and a broadening of the line width under the same pump intensity. However, in the experiment, this embodiment only injected 1mL of Nile red solution, and obtained a relatively long-lasting laser output with a small gain medium consumption, which met the needs of experimental characterization and provided a solution for the design of future miniaturized lasers.

[0057] Figures 8 to 10 This shows that the square metal nanoparticle array prepared by the present invention has a significant modulation effect on the incident light. Since the gain medium can provide sufficient optical gain to effectively compensate for the loss of the metal array itself, it can achieve higher quality laser emission and longer continuous working time.

[0058] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting, characterized in that: The steps of the method include: Step 1: Prepare a single-pass AAO pore array template by anodization method; Step 2: chemically etching the single-pass AAO hole array template to prepare a double-pass AAO template adhered to ITO; Step 3: Perform physical vapor deposition on the double-pass AAO template adhered to ITO, and remove the AAO template to obtain the metal plasmon resonant cavity required for the nano-laser device; Step 4: Based on the metal plasmon resonant cavity and gain material, a plasmon nanolaser is constructed to prepare a nanolaser chip.

2. The method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting according to claim 1, characterized in that: Step 1 specifically includes: Step 1.1: Cut the aluminum sheet into discs with a diameter of 2 cm, immerse the cut aluminum sheet in ultrapure water and clean it with ultrasound, take out the aluminum sheet after ultrasonic cleaning for 10 minutes, immerse it in ethanol and clean it with ultrasound, and after ultrasonic cleaning for 10 minutes, obtain the aluminum sheet after impurities are removed; Step 1.2: prepare a polishing agent from a mixture of perchloric acid and ethanol, place the polishing agent on a magnetic stirrer to make it flow, place a lead plate on the cathode of the magnetic stirrer, place an aluminum sheet on the anode of the magnetic stirrer, set the parameters of the magnetic stirrer and turn on the magnetic stirrer to allow the lead plate and the aluminum sheet to react in an ice water bath for 4 to 6 minutes, remove the rough surface of the aluminum sheet, and then use ultrapure water and ethanol to ultrasonically clean it again for 5 minutes in sequence; Step 1.3: Select a nickel film with a square period of 400nm as a template, use a sheet press to imprint the preset pattern on the surface of the aluminum sheet after ultrasonic cleaning, prepare an oxidizing solution, and use the oxidizing solution to anodize the imprinted aluminum sheet to obtain a single-pass AAO hole array template with a square period of 400nm.

3. The method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting according to claim 2, characterized in that: In step 1.2, the volume ratio of perchloric acid to ethanol is 1:7, and the parameters of the magnetic stirrer include: the reaction voltage is set to 30 V, the reaction current is set to 2 A / piece, and AAO is anodized aluminum oxide.

4. The method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting according to claim 2, characterized in that: In step 1.3, the pressure of the tablet press is 5 MPa, the imprinting time is 2 min, the oxidizing solution is composed of phosphoric acid, ethylene glycol and water, the volume ratio of phosphoric acid, ethylene glycol and water is 1:200:400, the anodizing environment is: constant voltage is 160 V, current is 0.015 A / piece, and oxidation time is 60 min.

5. The method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting according to claim 1, characterized in that: Step 2 specifically includes: Step 2.1: Use a spin coater to spin-coat the PMMA solution on the surface of the single-pass AAO hole array template, and cure it in a 30°C oven for 1 hour to protect the AAO surface and support the template. Place the cured single-pass AAO hole array template in a cupric chloride solution for a replacement reaction, so that the aluminum substrate at the bottom of the single-pass AAO hole array template corrodes and peels off, obtaining an AAO hole array template with a PMMA protective layer on the front side; Step 2.2: Fix the AAO hole array template with a PMMA protective layer on the front side with the back side facing up on a glass slide and immerse it in a phosphoric acid aqueous solution. Chemically etch the AAO film barrier layer for a preset time in a water bath at 55°C to obtain a square hole double-pass AAO template. Remove the square hole template from the glass slide and immerse it in analytical grade acetone to remove the attached PMMA. Use ITO to pick up the film and dry it. After the acetone is completely evaporated, a double-pass AAO template adhered to ITO is obtained, wherein ITO is a conductive glass.

6. The method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting according to claim 5, characterized in that: The PMMA solution in step 2.1 is a mixed solution of 1 g PMMA + 20 mL analytically pure CH2Cl2, the solidification time is 1 h, and the mass fraction of the phosphoric acid aqueous solution in step 2.2 is 5%.

7. The method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting according to claim 1, characterized in that: Step 3 specifically includes: The metal target material is evaporated on a double-pass AAO template adhered to ITO by physical vapor deposition. The metal vapor passes through the through holes of the double-pass AAO template and adheres to the ITO substrate to form a metal dot array. After the template is removed using a low-viscosity electrostatic tape, a uniformly distributed square metal nanoparticle array is obtained on the ITO surface, completing the preparation of the metal plasmon resonant cavity required for the nanolaser device.

8. The method for preparing a micro-nano array resonant cavity nano laser chip based on nanoimprinting according to claim 1, characterized in that: Step 4 specifically includes: The gain material is dissolved in anhydrous ethanol of analytical purity at a ratio of 1 mg:1 mL, and the gain material dissolved in anhydrous ethanol is injected into a groove consisting of two thin cover glasses bonded with UV-curing glue, and the square metal nanoparticle array on the ITO surface is placed in the groove and immersed in the gain material for compounding, wherein the gain material is Nile red.

Images