Use of solid material in optical system

Abstract

The present invention relates to the use of a solid material in an optical system, particularly the use of a solid material as a metasurface focusing lens material in an optical system. The solid material is a material containing at least one element of group IIIA, group IVA, group VA and group IIB of the periodic table of elements. The present invention solves the problem of large sizes caused by using external cooling structures to eliminate thermal drift in existing optical elements, the problem that traditional metalens materials facilitate miniaturization but are prone to thermal drift, and the problem of stringent design and processing conditions for 4H-SiC metalens materials, and has the advantages of balancing miniaturization and athermalization, reducing manufacturing costs and being suitable for large-batch production application.

Description

Application of a solid material in optical systems Technical Field

[0001] The present invention relates to the technical field of optical systems, and in particular to the application of solid materials in optical systems. Background Art

[0002] Optical instruments are a class of instruments that can generate light waves and display images, or receive light waves and analyze and determine their optical properties. They include optical metrology instruments, optical testing instruments, microscopy instruments, imaging software and devices, machine vision devices, multimedia microscopy interaction, optical machinery, metallography and hardness testers, optical surveying and mapping instruments, optical components, fiber optic instruments, optical testing instruments, digital optics, light sources and coatings, popular science optics, laser instruments, optoelectronic displays, medical optics, infrared thermal imaging, lenses, and more. As a crucial component of the instrumentation industry, optical instruments are indispensable tools for observation, testing, analysis, control, recording, and transmission in industrial and agricultural production, resource exploration, space exploration, scientific experiments, national defense construction, and various areas of social life. The volume and weight of optical systems account for a large proportion of the entire optical instrument, making their miniaturization and athermalization of optical systems of great significance.

[0003] In an optical system, when a light beam is reflected or refracted on the surface of various optical components such as lenses, mirrors, prisms, and apertures, the center position of the light beam will deviate due to the non-uniformity of the optical components. In addition, long-term irradiation of a high-power light beam causes a large amount of heat accumulation in the focusing lens, which will cause thermal expansion of the optical components, resulting in thermal drift of the center position of the light beam, and further resulting in problems such as thermal aberration. In order to reduce the adverse effects of thermal drift on optical imaging, measurement, and other applications, the following measures are usually taken: (1) Select appropriate optical materials to avoid the non-uniformity of optical components from having a significant impact on the light beam; (2) Consider the temperature effect of optical components during the design process of the optical system, and use cooling structures such as passive heat dissipation fins, active water-cooled heat exchangers, and cooling dewars to cool the optical components to prevent thermal drift; (3) Regularly calibrate and maintain the optical system, and adjust or replace optical components with problems in a timely manner to ensure the accuracy and stability of the optical system.

[0004] Chinese patent publication number CN104535193A discloses an infrared focal plane detector assembly comprising: imaging optical components, a cold screen, and a dewar. The imaging optical components, including a cryogenic filter, an objective lens, and a cold stop, are integrated within the dewar. The objective lenses include objective lenses 1, 2, and 3. Objective lens 1 is used as a window in the dewar to expand the field of view of the optical system. The cryogenic filter, objective lens 2, and objective lens 3 are bonded to the cold screen to ensure their correct optical position, and the objective lens is cooled to a stable temperature through conduction from the cold screen. This assembly uses the second method described above to cool the objective lens and other components, maintaining a constant low-temperature environment to avoid the adverse effects of thermal drift. However, this also results in a larger overall size of the imaging optical components, hindering the miniaturization of the optical system.

[0005] Chinese patent application CN114188815B discloses a lensless focusing device for a coherent array laser, comprising: a coherent array laser, a binary optical microstructure substrate, and a binary optical microstructure; the binary optical microstructure produces a phase modulation effect on the laser beam of each laser unit of the coherent array laser; the structural elements are all of subwavelength thickness; the binary optical microstructure is prepared by etching and then depositing optical materials with different refractive indices on the binary optical microstructure substrate; the binary optical microstructure substrate is a SiO2 substrate, and the binary optical microstructure is a Si3N4 layer. This device uses optical materials with different refractive indices to prepare a metalens (binary optical microstructure substrate and binary optical microstructure), achieving a lensless focusing effect, which to some extent overcomes the miniaturization difficulties of the original optical system. However, due to the low thermal conductivity of traditional metalens materials such as Si, SiO2, and Si3N4, thermal aberrations caused by heat accumulation still exist, which is not conducive to the athermalization of the optical system.

[0006] 4H-SiC is a representative third-generation semiconductor material. It is a wide-bandgap semiconductor material with a bandgap of 3.6 eV. Its transmittance in the visible and near-infrared wavelengths outside its bandgap is as high as 95%, making it a wide-bandgap lossless medium. Chinese patent publication number CN116736416A discloses a polarization-multiplexing metalens based on 4H-SiC and its design method. The metalens comprises multiple 4H-SiC subwavelength resonant structural units arranged in a two-dimensional array. Each 4H-SiC subwavelength resonant structural unit comprises a 4H-SiC substrate and 4H-SiC nanobricks disposed on the 4H-SiC substrate. The above-mentioned superlens needs to use 4H-SiC instead of traditional superlens materials and determine the geometric parameters of the 4H-SiC subwavelength resonant structure unit according to a predetermined design method to achieve a focusing efficiency of 75-85% at each focus in the visible light range. Compared with visible light optical materials, infrared and ultraviolet optical materials need to have a very high refractive index temperature variation coefficient. Since temperature changes have a more serious impact on the performance of such optical systems, under conventional design concepts, phase modulation can only be further used to correct and compensate for it. In addition, due to the high hardness and brittleness of 4H-SiC and the difficulty in processing, the manufacturing cost of the superlens will increase, which ultimately makes it difficult for such superlenses to be applied in large quantities in optical systems.

[0007] Summary of the Invention

[0008] The problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art and to provide an application of a solid material in an optical system. The present invention solves the problem of large volume caused by the external cooling structure of existing optical elements to eliminate thermal drift, the problem that traditional superlens materials are conducive to miniaturization but have thermal drift, and the problem that 4H-SiC superlens materials have harsh design and processing conditions. The present invention has the advantages of taking into account miniaturization and athermalization, reducing manufacturing costs, and being suitable for mass production applications.

[0009] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0010] The problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art and to provide an application of a solid material in an optical system. The present invention solves the problem of large volume caused by the external cooling structure of existing optical elements to eliminate thermal drift, the problem that traditional superlens materials are conducive to miniaturization but have thermal drift, and the problem that 4H-SiC superlens materials have harsh design and processing conditions. The present invention has the advantages of taking into account miniaturization and athermalization, reducing manufacturing costs, and being suitable for mass production applications.

[0011] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0012] A solid material is used in an optical system, wherein the solid material is used as a metasurface focusing lens material in the optical system, wherein the solid material is a material containing at least one element from the group consisting of IIIA, IVA, VA, and IIB elements of the periodic table.

[0013] Furthermore, the solid material is silicon carbide SiC, silicon germanium SiGe, germanium Ge, gallium arsenide GaAs, gallium nitride GaN, indium phosphide InP, indium arsenic antimony InAlSb, zinc oxide ZnO, aluminum nitride AlN, gallium trioxide Ga2O3, aluminum oxide Al2O3, gallium phosphide GaP, indium arsenide InAs, indium nitride InN, aluminum arsenide AlAs, diamond, cubic boron nitride CBN, magnesium silicate Mg2SiO4, lead titanate PbTiO3, barium titanate BaTiO3, lithium niobate LiNbO3, Al2O3CrNd glass, cadmium telluride CdTe, tungsten oxide WO3, zinc ferrite ZnFe2O, gamma iron oxide γ-Fe2O3, strontium ferrite SrO·6Fe2O3, cadmium sulfide CdS, calcium polysulfide Ca2Sx, vanadium oxide VO2, nickel oxide NiO, lanthanum boride LaB6, barium oxide BaO, lead magnesium niobate PMN, barium titanate BaTiO3, lithium titanate LiTiO3, yttrium aluminum garnet YAG, lithium niobate LiNbO3, gallium phosphate GaPO4, calcium titanate CaTiO3, rare earth ketonate YBa2Cu3O7, and a combination of one or more of the following metal materials.

[0014] Furthermore, the solid material is silicon carbide material or diamond material.

[0015] Furthermore, the solid material is one or a combination of 3C-SiC material, 4H-SiC material, 6H-SiC material and diamond material.

[0016] Furthermore, the metasurface focusing lens includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer, and the metasurface microstructure layer is composed of a solid material.

[0017] Alternatively, the metasurface focusing lens includes a light-transmitting base layer, a light-transmitting medium layer disposed on the light-transmitting base layer, and a metasurface microstructure layer disposed on the light-transmitting medium layer, wherein the light-transmitting medium layer is composed of a solid material.

[0018] Furthermore, the metasurface focusing lens is made of solid material. In other words, the metasurface focusing lens is made of solid material in one piece, which is beneficial to improving material uniformity.

[0019] Furthermore, the supersurface microstructure layer includes a plurality of subwavelength structural units arranged in a two-dimensional array, and the subwavelength structural unit includes a plurality of nanopillars arranged in a straight line and with decreasing widths. Wherein, the meaning of the two-dimensional array arrangement refers to that these subwavelength structural units are arranged along the first direction and arranged along the second direction, and the array arrangement formed thereby is parallel to the surface of the light-transmitting substrate layer, and the angle between the first direction and the second direction is -90 to 90°, specifically -90°, -75°, -60°, -45°, -30°, -15°, 0° (the first direction and the second direction coincide), 15°, 30°, 45°, 60°, 75° or 90°. In addition, the nanopillars in each subwavelength unit are arranged along the first direction, and the widths decrease in sequence. These nanopillars are preferably cylindrical, conical, truncated cone, prism, pyramid, prism, irregular rotation body and irregular polyhedron, or a combination thereof.

[0020] Furthermore, in the subwavelength structural unit, the etching depth d of the nanocolumn is 800-1200 nm, the middle width w is 200-450 nm, the period p between two adjacent nanocolumns is 600-800 nm, and the middle width difference Δw is 30-50 nm.

[0021] Furthermore, the process of preparing a metasurface focusing lens from solid materials includes:

[0022] S1 pre-treats the solid material by organic cleaning and inorganic cleaning to remove organic and inorganic substances remaining on the surface of the solid material;

[0023] S2 performs photolithographic processing on the solid material obtained in S1 to achieve patterning of the super surface microstructure region on the surface of the solid material layer;

[0024] S3: subjecting the solid material obtained in S2 to a thin film deposition process to deposit a metal mask on the surface of the solid material layer;

[0025] S4: subjecting the solid material obtained in S3 to a metal lift-off process to remove the metal mask in the non-supersurface microstructure area;

[0026] S5: subjecting the solid material obtained in S4 to dry etching (ICP-RIE) to etch the non-super-surface microstructure region of the solid material layer to a predetermined etching depth, and completing the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0027] S6 wet-etches the solid material obtained in S5 to remove the metal mask in the metasurface microstructure area, thereby obtaining a metasurface focusing lens.

[0028] Furthermore, the process of preparing the metasurface focusing lens from the solid material includes:

[0029] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 5 to 15 minutes and an ultrasonic frequency of 30 to 50 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0030] S2 photolithography, first place the solid material obtained in S1 on the center of the carrier of the scalping machine, and add photoresist (Zep520A, AZ1500, AZ4500, or AZ6100) for scalping, the amount of addition is 1 to 6 mL, the scalping speed is 2000 to 6000 rpm, and the scalping time is 1 to 3 minutes. After the scalping is completed, the solid material is placed on a hot plate at 100 to 180°C and baked for 1 to 3 minutes. Then, an electron beam lithography machine (EBL), an ultraviolet lithography machine, or a laser direct writing lithography machine is used to expose the scalped solid material. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 50 to 70 seconds. Then, the developed solid material is immersed in 200 mL of isopropanol for 25 to 35 seconds. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0031] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.01 to 0.50 nm / s, so as to deposit a metal mask with a thickness of 5 to 100 nm on the surface of the solid material layer;

[0032] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 1 to 12 hours, the water bath temperature is 60 to 100°C, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 5 to 20 minutes, and the ultrasonic frequency is 10 to 20kHz. Then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 50 to 70 seconds, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area. Then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 70 to 90 sccm, the power is 250 to 350 W, the reaction time is 5 to 20 minutes, and it is taken out and purged with nitrogen;

[0033] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 4-8 sccm of trifluoromethane, 15-20 sccm of sulfur hexafluoride, and 4-8 sccm of oxygen, the etching power being 400-600 W, the etching rate being 0.1-1 nm / s, and the etching depth being 800-1200 nm, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0034] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 10 to 30 minutes, then immerse the solid material in 200 mL of water for 50 to 70 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0035] Furthermore, the optical system is a microscope optical system, a telescope optical system, a camera optical system, a projection optical system, a laser optical system, a Fourier transform optical system, a scanning optical system, or a fiber optic system.

[0036] Furthermore, the optical system is a laser beam expansion optical system, a laser collimation optical system, or a laser focusing optical system.

[0037] In summary, the beneficial technical effects of the present invention are:

[0038] 1. The present invention utilizes solid materials such as silicon carbide or diamond and integrates them into a metasurface focusing lens with excellent refractive, focusing, and thermal conductivity properties. This replaces the previous combination of a focusing objective lens and an external cooling structure, or the focusing solution of a SiO2 / Si3N4 metalens. While miniaturizing the optical system, it also improves the thermal drift problem caused by long-term irradiation of high-power beams, helps reduce the focal diameter and the amount of focus offset due to temperature increase, and enhances the thermal stability of the focusing optical elements in the optical system.

[0039] 2. This invention utilizes subwavelength structural units configured as gradient nanopillars and arranges them in a two-dimensional array to synergize the thermal properties of the solid material with the metasurface focusing lens structure. This allows for beam focusing by manipulating the amplitude and phase of the incident light, resulting in greater design freedom and a smaller focal diameter. Adjustment of the focal diameter can be achieved simply by adjusting the number and mid-section width of the nanopillars in the subwavelength structural units.

[0040] 3. This invention reduces the processing difficulty and manufacturing cost of solid materials such as silicon carbide or diamond by first depositing a metal mask composed of aluminum, silver, gold, chromium, etc. on the non-metasurface microstructure area of ​​the solid material, and then etching it with a fluorine-based gas. This produces a metasurface focusing lens with a high aspect ratio of 1:5, high refractive index, high thermal conductivity, and excellent focusing effect, making it suitable for mass production.

[0041] 4. The solid material used in the present invention as the metasurface focusing lens material can be applied to optical systems of visible light and invisible light, especially for high-power light beams such as ultraviolet lasers and infrared lasers. The focus thermal drift is extremely small under long-term irradiation. It has the advantages of taking into account miniaturization and athermalization, reducing manufacturing costs, and being suitable for large-scale applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG1 is a schematic structural diagram of a metasurface focusing lens obtained in Example 1 of the present invention.

[0043] FIG2 is a SEM image of the metasurface focusing lens obtained in Example 1 of the present invention at 300 times magnification and 45° tilt.

[0044] FIG3 is a SEM image of the metasurface focusing lens obtained in Example 1 of the present invention at 5000 times magnification and 45° tilt.

[0045] FIG4 is a SEM image of the metasurface focusing lens obtained in Example 1 of the present invention at a magnification of 15,000 times and an angle of 45°.

[0046] FIG5 is a SEM image of the metasurface focusing lens obtained in Example 1 of the present invention magnified 10,000 times and observed vertically.

[0047] FIG6 is an AFM image of the metasurface focusing lens obtained in Example 1 of the present invention.

[0048] FIG7 is a focal field distribution diagram of the metasurface focusing lens obtained in Example 1 of the present invention.

[0049] FIG8 is a focus test diagram of the metasurface focusing lens obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0050] In order to make the technical means, creative features, objectives and functions achieved by the present invention clearer and easier to understand, the present invention is further explained below with reference to the accompanying drawings and specific implementation methods.

[0051] Example 1: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0052] First, in terms of the type of solid material, this embodiment preferably uses 4H-SiC material as the solid material, with a refractive index of 2.6 and a thermal conductivity of 3.7 W / cm·K.

[0053] Secondly, in terms of the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, and includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cones with a slope of 0 to 30°, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle widths w of these nanopillars are 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0054] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0055] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0056] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0057] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.20 nm / s, to deposit a metal mask with a thickness of 50 nm on the surface of the solid material layer;

[0058] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 6h, the water bath temperature is 80℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 15min, the ultrasonic frequency is 15kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 60s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 80sccm, the power is 300W, the reaction time is 15min, and it is taken out and purged with nitrogen;

[0059] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 6 sccm of trifluoromethane, 18 sccm of sulfur hexafluoride, and 6 sccm of oxygen, the etching power being 500 W, and the etching rate being 0.8 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0060] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 20 minutes, then immerse the solid material in 200 mL of water for 60 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0061] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of a laser wavelength of 1064nm, a laser power of 10W, and a pulse width of 130fs, the performance test was carried out. The results showed that the minimum focal diameter was 1.5μm, the focus offset during heating was 0.5μm / ℃, the refractive index of the metasurface focusing lens was 2.6462@589nm, and the thermal conductivity of the metasurface focusing lens was 490W / cm·K.

[0062] The fabricated metasurface focusing lens was subjected to macroscopic inspection, and the results are shown in Figure 1. As can be seen from Figure 1, the length and width of the metasurface focusing lens are within the range of 1 to 2 cm, and its thickness does not exceed 1 mm, which is conducive to the integration and miniaturization of optical systems.

[0063] The resulting metasurface focusing lens was subjected to microscopic inspection, and the results are shown in Figures 2 to 7. Figures 2 to 7 show that by first depositing a metal mask composed of aluminum, silver, gold, chromium, etc. on the non-metasurface microstructure area of ​​the solid material and then etching it with a fluorine-based gas, the target structure can be precisely machined with excellent focusing performance.

[0064] The focal field distribution of the fabricated metasurface focusing lens was tested, and the results are shown in Figure 8. As can be seen from Figure 8, the theoretical values ​​of the metasurface focusing lens are consistent with the measured values. The focal diameter can be adjusted simply by adjusting the number of nanopillars and the width of the middle part in the subwavelength structural unit.

[0065] Example 2: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0066] First, in terms of the type of solid material, this embodiment preferably uses 4H-SiC material as the solid material.

[0067] Secondly, in terms of the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, and includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 6 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 800nm, and the middle widths w of these nanopillars are 210, 260, 290, 310, 370, and 440nm, respectively.

[0068] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0069] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0070] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0071] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.20 nm / s, to deposit a metal mask with a thickness of 50 nm on the surface of the solid material layer;

[0072] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 6h, the water bath temperature is 80℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 15min, the ultrasonic frequency is 15kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 60s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 80sccm, the power is 300W, the reaction time is 15min, and it is taken out and purged with nitrogen;

[0073] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 6 sccm of trifluoromethane, 18 sccm of sulfur hexafluoride, and 6 sccm of oxygen, the etching power being 500 W, and the etching rate being 0.8 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0074] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 20 minutes, then immerse the solid material in 200 mL of water for 60 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0075] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 2.5μm, and the focus offset during heating was 0.7μm / ℃.

[0076] Example 3: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0077] First, in terms of the type of solid material, this embodiment preferably uses 6H-SiC material as the solid material.

[0078] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle width w of these nanopillars is 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0079] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0080] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0081] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0082] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.20 nm / s, to deposit a metal mask with a thickness of 50 nm on the surface of the solid material layer;

[0083] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 6h, the water bath temperature is 80℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 15min, the ultrasonic frequency is 15kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 60s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 80sccm, the power is 300W, the reaction time is 15min, and it is taken out and purged with nitrogen;

[0084] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 6 sccm of trifluoromethane, 18 sccm of sulfur hexafluoride, and 6 sccm of oxygen, the etching power being 500 W, and the etching rate being 0.8 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0085] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 20 minutes, then immerse the solid material in 200 mL of water for 60 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0086] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 2.3μm, and the temperature increase focal offset was 0.6μm / ℃.

[0087] Example 4: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0088] First, in terms of the type of solid material, this embodiment preferably uses 3C-SiC material as the solid material.

[0089] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 6 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle widths w of these nanopillars are 200, 255, 285, 310, 340, and 370nm, respectively.

[0090] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0091] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0092] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0093] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.20 nm / s, to deposit a metal mask with a thickness of 50 nm on the surface of the solid material layer;

[0094] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 6h, the water bath temperature is 80℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 15min, the ultrasonic frequency is 15kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 60s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 80sccm, the power is 300W, the reaction time is 15min, and it is taken out and purged with nitrogen;

[0095] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 6 sccm of trifluoromethane, 18 sccm of sulfur hexafluoride, and 6 sccm of oxygen, the etching power being 500 W, and the etching rate being 0.8 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0096] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 20 minutes, then immerse the solid material in 200 mL of water for 60 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0097] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of a laser wavelength of 1064nm, a laser power of 10W, and a pulse width of 130fs, the performance test was carried out. The minimum focal diameter was measured to be 3.1μm, and the focus offset during heating was 0.8μm / ℃.

[0098] Example 5: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0099] First, in terms of the type of solid material, this embodiment preferably uses diamond material as the solid material.

[0100] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle width w of these nanopillars is 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0101] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0102] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0103] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0104] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.20 nm / s, to deposit a metal mask with a thickness of 50 nm on the surface of the solid material layer;

[0105] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 6h, the water bath temperature is 80℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 15min, the ultrasonic frequency is 15kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 60s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 80sccm, the power is 300W, the reaction time is 15min, and it is taken out and purged with nitrogen;

[0106] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 6 sccm of trifluoromethane, 18 sccm of sulfur hexafluoride, and 6 sccm of oxygen, the etching power being 500 W, and the etching rate being 0.8 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0107] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 20 minutes, then immerse the solid material in 200 mL of water for 60 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0108] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 1.8μm, and the temperature increase focal offset was 0.5μm / ℃.

[0109] Example 6: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0110] First, in terms of the type of solid material, this embodiment preferably uses 4H-SiC material as the solid material.

[0111] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle width w of these nanopillars is 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0112] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0113] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 5 min and an ultrasonic frequency of 30 kHz, and then blow dry the solid material with nitrogen to remove the organic and inorganic substances remaining on the surface of the solid material;

[0114] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 1 mL, the spin coating speed is 2000 rpm, and the spin coating time is 1 min. After the spin coating is completed, the solid material is placed on a hot plate at 100°C and baked for 1 min. Then, the solid material after spin coating is exposed using an electron beam lithography machine (EBL). The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 50 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 25 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0115] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.20 nm / s, to deposit a metal mask with a thickness of 50 nm on the surface of the solid material layer;

[0116] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 6h, the water bath temperature is 80℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 15min, the ultrasonic frequency is 15kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 60s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 80sccm, the power is 300W, the reaction time is 15min, and it is taken out and purged with nitrogen;

[0117] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 6 sccm of trifluoromethane, 18 sccm of sulfur hexafluoride, and 6 sccm of oxygen, the etching power being 500 W, and the etching rate being 0.8 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0118] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 20 minutes, then immerse the solid material in 200 mL of water for 60 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0119] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 1.6μm, and the temperature increase focal offset was 0.5μm / ℃.

[0120] Example 7: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0121] First, in terms of the type of solid material, this embodiment preferably uses 4H-SiC material as the solid material.

[0122] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle width w of these nanopillars is 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0123] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0124] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 15 min and an ultrasonic frequency of 50 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0125] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 6 mL, the spin coating speed is 6000 rpm, and the spin coating time is 3 min. After the spin coating is completed, the solid material is placed on a hot plate at 180°C and baked for 3 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 70 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 35 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0126] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.20 nm / s, to deposit a metal mask with a thickness of 50 nm on the surface of the solid material layer;

[0127] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 6h, the water bath temperature is 80℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 15min, the ultrasonic frequency is 15kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 60s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 80sccm, the power is 300W, the reaction time is 15min, and it is taken out and purged with nitrogen;

[0128] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 6 sccm of trifluoromethane, 18 sccm of sulfur hexafluoride, and 6 sccm of oxygen, the etching power being 500 W, and the etching rate being 0.8 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0129] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 20 minutes, then immerse the solid material in 200 mL of water for 60 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0130] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of a laser wavelength of 1064nm, a laser power of 10W, and a pulse width of 130fs, the performance test was carried out. The minimum focal diameter was measured to be 1.6μm, and the focus offset during heating was 0.5μm / ℃.

[0131] Example 8: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0132] First, in terms of the type of solid material, this embodiment preferably uses 4H-SiC material as the solid material.

[0133] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle width w of these nanopillars is 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0134] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0135] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0136] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0137] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.01 nm / s, to deposit a metal mask with a thickness of 5 nm on the surface of the solid material layer;

[0138] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 1h, the water bath temperature is 60℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 5min, the ultrasonic frequency is 10kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 50s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 70sccm, the power is 250W, the reaction time is 5min, and it is taken out and purged with nitrogen;

[0139] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 4 sccm of trifluoromethane, 15 sccm of sulfur hexafluoride, and 4 sccm of oxygen, the etching power being 400 W, and the etching rate being 0.1 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0140] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 10 minutes, then immerse the solid material in 200 mL of water for 50 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0141] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 2.1μm, and the temperature increase focal offset was 0.6μm / ℃.

[0142] Example 9: Application of a solid material disclosed in the present invention in an optical system, specifically application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0143] First, in terms of the type of solid material, this embodiment preferably uses 4H-SiC material as the solid material.

[0144] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle width w of these nanopillars is 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0145] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0146] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0147] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0148] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.10 nm / s, to deposit a metal mask with a thickness of 75 nm on the surface of the solid material layer;

[0149] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 5h, the water bath temperature is 75℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 10min, the ultrasonic frequency is 18kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 65s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 85sccm, the power is 280W, the reaction time is 10min, and it is taken out and purged with nitrogen;

[0150] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 7 sccm of trifluoromethane, 16 sccm of sulfur hexafluoride, and 5 sccm of oxygen, the etching power being 550 W, and the etching rate being 0.5 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0151] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 15 minutes, then immerse the solid material in 200 mL of water for 55 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0152] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 1.9μm, and the heating focus offset was 0.5μm / ℃.

[0153] Example 10: Application of a solid material disclosed herein in an optical system, specifically, application of the solid material as a metasurface focusing lens material in an optical system. The solid material comprises at least one element from Group IIIA, Group IVA, Group VA, and Group IIB of the periodic table.

[0154] First, in terms of the type of solid material, this embodiment preferably uses 4H-SiC material as the solid material.

[0155] Secondly, in the structural design of the metasurface focusing lens, the metasurface focusing lens of this embodiment is made of solid material as a whole, which includes a light-transmitting substrate layer and a metasurface microstructure layer arranged on the light-transmitting substrate layer. Among them, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along a first direction and a second direction, and each subwavelength structural unit includes 8 nanopillars arranged in a straight line along the first direction and with decreasing widths, and the angle between the first direction and the second direction is 90°. In the subwavelength structural unit, these nanopillars are truncated cone-shaped, the etching depth d of the nanopillars is 1000nm, the period p between two adjacent nanopillars is 600nm, and the middle width w of these nanopillars is 200, 240, 280, 310, 340, 370, 410, and 450nm, respectively.

[0156] Again, in the process design of the metasurface focusing lens, it includes the following steps:

[0157] S1 pretreatment: first, ultrasonically clean the solid material with acetone, ethanol, and isopropanol in sequence, with an ultrasonic time of 10 min and an ultrasonic frequency of 40 kHz, and then blow dry the solid material with nitrogen to remove residual organic and inorganic matter on the surface of the solid material;

[0158] S2 photolithography: first place the solid material obtained in S1 on the center of the carrier of the spin coater, and add photoresist (Zep520A) for spin coating. The amount of addition is 4 mL, the spin coating speed is 4000 rpm, and the spin coating time is 2 min. After the spin coating is completed, the solid material is placed on a hot plate at 150°C and baked for 2 min. Then, an electron beam lithography machine (EBL) is used to expose the solid material after spin coating. The exposed solid material is then immersed in 200 mL of developer (Zep-N50) for 60 s. Then, the developed solid material is immersed in 200 mL of isopropanol for 30 s. The solid material is blown dry with nitrogen to achieve patterning of the super surface microstructure area on the surface of the solid material layer.

[0159] S3 thin film deposition, using electron beam evaporation equipment to uniformly deposit aluminum, silver, gold and chromium in sequence on the surface of the solid material obtained in S2, with a deposition rate of 0.80nm / s, to deposit a metal mask with a thickness of 100nm on the surface of the solid material layer;

[0160] S4 metal stripping, first immerse the solid material obtained in S3 in 200mL stripping solution (N-methylpyrrolidone) with the metal mask facing up, seal and heat in a water bath for 12h, the water bath temperature is 100℃, and after the water bath heating is completed, perform ultrasonic treatment, the ultrasonic time is 20min, the ultrasonic frequency is 20kHz, and then use a disposable dropper to bubble in the stripping solution to blow the metal mask fragments suspended in the stripping solution and the metal mask in the non-supersurface microstructure area of ​​the solid material away from the supersurface microstructure area, and then immerse the solid material in 200mL isopropanol for 70s, rinse the solid material with isopropanol, and blow dry the solid material with nitrogen to remove the metal mask in the non-supersurface microstructure area, then put the stripped solid material into a plasma cleaning machine, the reaction gas is oxygen, the gas flow rate is 90sccm, the power is 350W, the reaction time is 20min, and it is taken out and purged with nitrogen;

[0161] S5 dry etching, using an inductively coupled plasma etching device (ICP-RIE) to etch the solid material obtained in S4, with the etching gas and its flow rate being 8 sccm of trifluoromethane, 20 sccm of sulfur hexafluoride, and 8 sccm of oxygen, the etching power being 600 W, and the etching rate being 1 nm / s, so as to etch the non-super-surface microstructure area of ​​the solid material layer to a predetermined etching depth d, and complete the transfer of the super-surface microstructure pattern between the metal mask and the solid material;

[0162] S6 wet etching: first immerse the solid material obtained in S5 in 200 mL of mask removal solution (a mixture of nitric acid and ammonium cerium nitrate) for 30 minutes, then immerse the solid material in 200 mL of water for 70 seconds, and blow dry the solid material with nitrogen to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

[0163] Finally, the prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of a laser wavelength of 1064nm, a laser power of 10W, and a pulse width of 130fs, the performance test was carried out. The minimum focal diameter was measured to be 1.7μm, and the focus offset during heating was 0.6μm / ℃.

[0164] Comparative Example 1: This is an application of a solid material disclosed in the present invention in an optical system. The difference from Example 1 is that, in terms of the type of solid material selected, this example preferably uses Si3N4 material as the solid material.

[0165] The prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 5.7μm, and the focus offset during heating was 1.8μm / ℃.

[0166] Comparative Example 2: This is an application of a solid material disclosed in the present invention in an optical system. The difference from Example 1 is that, in terms of the type of solid material selected, this example preferably uses SiO2 material as the solid material.

[0167] The prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 6.8μm, and the focus offset during heating was 2.4μm / ℃.

[0168] Comparative Example 3: This is an application of a solid material disclosed in the present invention in an optical system. The difference from Example 1 is that in the structural design of the metasurface focusing lens, the metasurface microstructure layer includes a plurality of subwavelength structural units arranged in an array along the first direction and the second direction, and each subwavelength structural unit includes 8 nanocolumns arranged in a straight line along the first direction and with a central width of 280 nm. The angle between the first direction and the second direction is 90°.

[0169] The prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 4.5μm, and the focus offset during heating was 1.5μm / ℃.

[0170] Comparative Example 4: This is an application of a solid material disclosed in the present invention in an optical system. The difference from Example 1 is that S3, S4 and S6 are not included in the process design of the metasurface focusing lens.

[0171] The prepared metasurface focusing lens was installed on the laser focusing optical system between the laser and the processed sample. After irradiation for 10 minutes under the focusing conditions of laser wavelength 1064nm, laser power 10W, and pulse width 130fs, the performance test was carried out. The minimum focal diameter was measured to be 3.7μm, and the focus offset during heating was 1.2μm / ℃.

[0172] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. Application of a solid material in an optical system, characterized in that: The solid material is used as a metasurface focusing lens material in an optical system, wherein the solid material is a material containing at least one element of the IIIA group elements, IVA group elements, VA group elements and IIB group elements of the periodic table.

2. The use of a solid material in an optical system according to claim 1, characterized in that: The solid material is silicon carbide material or diamond material.

3. The use of a solid material in an optical system according to claim 1, characterized in that: The supersurface focusing lens comprises a light-transmitting substrate layer and a supersurface microstructure layer arranged on the light-transmitting substrate layer, wherein the supersurface microstructure layer is composed of solid material.

4. The use of a solid material in an optical system according to claim 1, characterized in that: The supersurface focusing lens comprises a light-transmitting substrate layer, a light-transmitting medium layer arranged on the light-transmitting substrate layer, and a supersurface microstructure layer arranged on the light-transmitting medium layer, wherein the light-transmitting medium layer is composed of solid material.

5. Use of a solid material according to claim 3 or 4 in an optical system, characterized in that: The metasurface focusing lens is composed of solid material.

6. Use of a solid material according to claim 3 or 4 in an optical system, characterized in that: The super-surface microstructure layer includes a plurality of sub-wavelength structure units arranged in a two-dimensional array, and the sub-wavelength structure unit includes a plurality of nano-pillars arranged in a straight line and with decreasing widths.

7. The use of a solid material in an optical system according to claim 6, characterized in that: In the sub-wavelength structural unit, the etching depth of the nanocolumn is 800-1200nm, the middle width is 200-450nm, the period between two adjacent nanocolumns is 600-800nm, and the middle width difference is 30-50nm.

8. The use of a solid material in an optical system according to claim 1, characterized in that: The process of preparing a supersurface focusing lens from a solid material comprises: S1 pre-treats the solid material by organic cleaning and inorganic cleaning to remove organic and inorganic substances remaining on the surface of the solid material; S2 performs photolithography on the solid material obtained in S1 to achieve patterning of the ultra-surface microstructure region on the surface of the solid material layer; S3 processes the solid material obtained in S2 through thin film deposition to deposit a metal mask on the surface of the solid material layer; S4: subjecting the solid material obtained in S3 to a metal stripping process to remove the metal mask in the non-supersurface microstructure area; S5: subjecting the solid material obtained in S4 to dry etching to etch the non-super-surface microstructure region of the solid material layer to a predetermined etching depth, and completing the transfer of the super-surface microstructure pattern between the metal mask and the solid material; S6 wet-etches the solid material obtained in S5 to remove the metal mask in the metasurface microstructure area to obtain a metasurface focusing lens.

9. The use of a solid material in an optical system according to claim 1, characterized in that: The optical system is a microscope optical system, a telescope optical system, a camera optical system, a projection optical system, a laser optical system, a Fourier transform optical system, a scanning optical system, or a fiber optical system.

10. The use of a solid material in an optical system according to claim 9, characterized in that: The optical system is a laser beam expansion optical system, a laser collimation optical system, or a laser focusing optical system.

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