Ultra-smooth spectroscope and preparation method thereof

Abstract

The invention belongs to the technical field of optical element processing, and particularly relates to a super-smooth spectroscope and a preparation method thereof. The preparation method of the ultra-smooth spectroscope comprises the following steps: mixing a pretreated nano-composite quartz material and silicon nitride, and grinding by adopting an ultrasonic-assisted nano-diamond abrasive grinding technology to obtain a mixture; polishing the mixture by adopting a plasma-assisted chemical polishing technology to obtain a polished mixture; carrying out nanometer processing on the polished mixture by adopting a femtosecond laser direct writing technology to obtain a spectroscope structural member; carrying out optical simulation and optimization on a plurality of nano-scale film layers, and carrying out multi-layer nano-scale film coating on the surface of the spectroscope structural member by adopting an atomic layer deposition technology; meanwhile, the thickness of the multiple nanoscale film layers is monitored and adjusted in real time; and carrying out surface enhancement treatment on the coated spectroscope structural member to obtain the ultra-smooth spectroscope.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical element processing, and particularly relates to an ultra-smooth beam splitter and a preparation method thereof. Background Art

[0002] Ultra-smooth beam splitters have important application values in the optical field, so the research significance of their preparation methods has also become prominent. A beam splitter is an optical device widely used for spectral analysis, and the smoothness of its surface has an important impact on experimental results. Therefore, improving the optical surface quality of beam splitters has been one of the long-term pursuit goals of scientific researchers. In this context, researching a preparation method for ultra-smooth beam splitters is of great significance for promoting the development of the optical field.

[0003] First of all, the research on the preparation method of ultra-smooth beam splitters can promote the performance optimization of optical devices. As an important optical element, the performance of a beam splitter directly affects the resolution and accuracy of optical instruments. A beam splitter of higher quality can improve the working efficiency of an optical system and make experimental results more accurate and reliable. Therefore, by researching the preparation method of ultra-smooth beam splitters, the performance of optical devices can be further optimized, promoting the development of optical technology.

[0004] Secondly, the research on the preparation method of ultra-smooth beam splitters can also expand the application fields of optical devices. With the continuous development of science and technology, the demand for optical devices is also increasing. As an important part of the optical field, the research on the preparation method of ultra-smooth beam splitters can enable them to be applied in a wider range of fields, such as laser technology, optical communication, optical imaging and other fields. Therefore, by researching the preparation method of ultra-smooth beam splitters, the application fields of optical devices can be continuously expanded, promoting the innovation and application of optical technology.

[0005] In addition, the research on the preparation method of ultra-smooth beam splitters can also promote the development of optical materials. Optical materials are an important basis for preparing optical devices, and their performance is directly related to the quality and performance of optical devices. Researching the preparation method of ultra-smooth beam splitters can explore the applicability and advantages and disadvantages of different optical materials in the preparation process, providing more choices for researchers. By continuously improving the preparation process and performance of optical materials, the preparation efficiency and quality of beam splitters can be improved, promoting the development and application of optical devices.

[0006] With the continuous progress of science and technology, people's requirements for optical components are also getting higher and higher. The traditional methods for preparing ultra-smooth components mainly include mechanical polishing and ion beam polishing. However, the mechanical polishing method achieves high-precision surface smoothness through mechanical grinding and polishing. This method has disadvantages such as low efficiency, high cost, and easy generation of scratches. At the same time, after the mechanical polishing process, the surface roughness is usually above 1nm, which cannot meet the requirements of high-precision optical applications. Ion beam polishing is a modern method for preparing ultra-smooth beam splitters, which uses the bombardment of ion beams to remove surface impurities and improve the surface smoothness of the beam splitters. However, ion beam polishing may cause changes in the surface topography, affecting the performance of the beam splitters. Therefore, it is urgent to continuously improve the existing technology and develop a more efficient and precise method for preparing ultra-smooth beam splitters. Summary of the Invention The purpose of the present invention is to provide a method for preparing an ultra-smooth beam splitter to solve the problems of low precision and efficiency in obtaining ultra-smooth components by the existing methods for preparing beam splitters.

[0007] To solve the above problems, the present invention proposes a method for preparing an ultra-smooth beam splitter, and the technical solution adopted is as follows: A method for preparing an ultra-smooth beam splitter includes the following steps: Step S1: After mixing the pretreated nano-composite quartz material and silicon nitride, grind them using ultrasonic-assisted nano-diamond abrasive grinding technology to obtain a mixed material; Step S2: Polish the mixed material using plasma-assisted chemical polishing technology to obtain the polished mixed material; Step S3: Perform nano-processing on the polished mixed material using femtosecond laser direct writing technology to obtain a beam splitter structural component; at the same time, use optical coherence tomography technology to monitor in real time the changes in the surface topography of the beam splitter structural component during the processing of the femtosecond laser direct writing technology; Step S4: Conduct optical simulation and optimization of the multi-layer nano-scale film layer, and use atomic layer deposition technology to deposit a multi-layer nano-scale film on the surface of the beam splitter structural component; at the same time, monitor and adjust the thickness of the multi-layer nano-scale film layer in real time according to the optical simulation and optimization of the multi-layer nano-scale film layer; Step S5: Perform surface enhancement treatment on the coated beam splitter structural component to obtain an ultra-smooth beam splitter.

[0008] Further, in step S1, during the grinding using ultrasonic-assisted nano-diamond abrasive grinding technology, monitor in real time the surface topography and roughness of the nano-composite quartz material and silicon nitride; and the surface roughness of the ground nano-composite quartz material and silicon nitride is below 1nm.

[0009] Further, in step S2, the plasma-assisted chemical polishing technology specifically includes: Under the action of a nano-catalyst, polishing is carried out by plasma-assisted chemical polishing technology in an environment of 20-60 °C; the surface roughness of the polished nano-composite quartz material and silicon nitride is ≤0.05 nm.

[0010] Further, in step S3, in the femtosecond laser direct writing technology, the laser pulse time is 50-300 fs and the energy is 50-500 nJ.

[0011] Further, in step S4, optical simulation and optimization of the multi-layer nano-scale film layer are carried out, and atomic layer deposition technology is used to deposit a multi-layer nano-scale film on the surface of the spectroscope structural member; meanwhile, real-time monitoring and adjustment of the thickness of the multi-layer nano-scale film layer according to the optical simulation and optimization of the multi-layer nano-scale film layer specifically include: First, optical simulation and optimization are carried out on the refractive index matching, spectral transmittance and reflectance of the multi-layer nano-scale film layer; then, atomic layer deposition technology is used to deposit nano-scale thin films layer by layer on the surface of the spectroscope structural member to obtain a multi-layer nano-scale film layer; meanwhile, during the processing of atomic layer deposition technology, ellipsometry and quartz crystal microbalance are used for real-time monitoring of the thickness of the multi-layer nano-scale film layer, and according to the optical simulation and optimization of the multi-layer nano-scale film layer, the process parameters of atomic layer deposition technology are dynamically adjusted, thereby adjusting the thickness of the multi-layer nano-scale film layer.

[0012] Further, during the process of depositing nano-scale thin films layer by layer on the surface of the spectroscope structural member by atomic layer deposition technology, the film layer thickness is controlled at 0.1-0.2 nm / cycle, and the thickness of the multi-layer nano-scale film layer is 50 -150 nm.

[0013] Further, in step S5, the surface enhancement treatment includes: First, the surface of the coated spectroscope structural member after coating is treated by high-energy ion beam technology and laser annealing technology.

[0014] Further, the preparation method further includes: During the process of step S1-step S5, the preparation process of each step is monitored in real time, and the defects occurring in the corresponding steps are timely fed back, so as to achieve automatic correction.

[0015] Further, in step S1, the pretreatment includes plasma surface cleaning and surface activation treatment. This application also provides a super-smooth spectroscope, which is prepared by the preparation method of the above-mentioned super-smooth spectroscope.

[0016] Compared with the prior art, this application has the following beneficial effects: The present invention is an improved invention. The present invention uses a nanocomposite material and high-strength silicon nitride to improve the mechanical strength and thermal stability of the spectroscope; uses ultrasonic-assisted nano-diamond abrasive grinding technology for grinding to improve the surface finish of the material; uses femtosecond laser direct writing technology for nano-processing to form a high-precision nanostructure and improve the optical performance; at the same time, uses optical coherence tomography technology to monitor in real time the surface topography changes of the spectroscope structural components during the processing of the femtosecond laser direct writing technology to ensure the accuracy of the spectroscope structural components; uses atomic layer deposition technology to perform multi-layer nano-scale coating on the surface of the spectroscope structural components to achieve nano-scale thickness control. At the same time, according to the optical simulation and optimization of the multi-layer nano-scale film layer, the thickness of the multi-layer nano-scale film layer is monitored and adjusted in real time to ensure the coating uniformity and high quality; finally, through surface enhancement treatment, the film layer adhesion and anti-damage properties are improved, and then a super-smooth spectroscope is prepared. The processing technology of the spectroscope in this application has achieved major breakthroughs in aspects such as material selection, processing accuracy, and surface treatment, enabling the surface roughness of the spectroscope to reach 0.088 nm, significantly improving the optical performance of the spectroscope, and solving the problems existing in the traditional preparation methods of super-smooth components, such as low efficiency, high cost, easy scratching, inability to achieve high roughness, and inability to guarantee the surface topography; at the same time, it can also significantly improve the processing efficiency, which is of great significance for the application of high-precision optical systems.

[0017] In step S1, during the grinding process using ultrasonic-assisted nano-diamond abrasive grinding technology, the surface topography and roughness of the nanocomposite quartz material and silicon nitride are monitored in real time; and the surface roughness of the nanocomposite quartz material and silicon nitride after grinding is below 1 nm, improving the cutting efficiency and uniformity of the abrasive, and thus improving the surface roughness of the material.

[0018] In step S2, the plasma-assisted chemical polishing technology specifically includes: Under the environment of 20 - 60 °C, polishing is carried out by plasma-assisted chemical polishing technology under the action of a nano-catalyst; the surface roughness of the nanocomposite quartz material and silicon nitride after polishing is ≤ 0.05 nm, improving the surface finish of the material.

[0019] In step S4, the optical simulation and optimization of the multi-layer nano-scale film layer are carried out, and atomic layer deposition technology is used to perform multi-layer nano-scale coating on the surface of the spectroscope structural components; at the same time, the specific content of monitoring and adjusting the thickness of the multi-layer nano-scale film layer in real time according to the optical simulation and optimization of the multi-layer nano-scale film layer includes: First, perform optical simulation and optimization on the refractive index matching, spectral transmittance, and reflectance of the multi-layer nanoscale film layer; then, use atomic layer deposition technology to deposit nanoscale thin films layer by layer on the surface of the spectroscope structural member to obtain a multi-layer nanoscale film layer; meanwhile, during the processing of atomic layer deposition technology, use ellipsometry and quartz crystal microbalance to monitor the thickness of the multi-layer nanoscale film layer in real time, and dynamically adjust the process parameters of atomic layer deposition technology according to the optical simulation and optimization of the multi-layer nanoscale film layer, thereby adjusting the thickness of the multi-layer nanoscale film layer to ensure film layer uniformity and optical performance stability, and achieve high transmittance and precise spectral splitting ratio.

[0020] In step S5, the surface enhancement treatment includes: First, use high-energy ion beam technology and laser annealing technology to treat the surface of the coated spectroscope structural member after coating to increase the density and surface hardness of the film layer and improve the durability of the film layer.

[0021] The preparation method further includes: During the process of step S1-step S5, monitor the preparation process of each step in real time, and give timely feedback on the defects that occur in the corresponding steps, so as to achieve automatic correction, improve processing accuracy and efficiency.

[0022] In step S1, the pretreatment includes plasma surface cleaning and surface activation treatment to remove surface impurities, increase the surface energy state, and improve the material adhesion in subsequent processing and coating steps. Description of the Drawings Figure 1 is a schematic flow chart of the preparation method of the ultra-smooth spectroscope of the present invention; Figure 2 is a schematic diagram of the simulation result of the ultra-smooth spectroscope prepared by the preparation method of the ultra-smooth spectroscope of the present invention; Figure 3 is a physical diagram of the ultra-smooth spectroscope prepared by the preparation method of the ultra-smooth spectroscope of the present invention; Figure 4 is a surface profile diagram of the ultra-smooth spectroscope prepared by the preparation method of the ultra-smooth spectroscope of the present invention; Figure 5 is a roughness characterization diagram of the ultra-smooth spectroscope prepared by the preparation method of the ultra-smooth spectroscope of the present invention. Detailed Embodiment

[0023] As cited in the background art, the prior art methods for preparing beam splitters have low precision and efficiency in obtaining super-smooth components. Therefore, the present invention provides a method for preparing a super-smooth beam splitter. First, the pretreated nano-composite quartz material and silicon nitride are mixed to improve the mechanical strength and thermal stability of the beam splitter, and ultrasonic-assisted nano-diamond abrasive grinding technology is used for grinding to obtain a mixture, improving the surface finish. Secondly, plasma-assisted chemical polishing technology is used to polish the mixture to obtain the polished mixture, which is used to improve the uniformity and finish of the mixture. Then, the polished mixture is subjected to nano-processing using femtosecond laser direct writing technology to obtain a beam splitter structural component. At the same time, optical coherence tomography technology is used to monitor in real time the change in the surface topography of the beam splitter structural component during the processing of the femtosecond laser direct writing technology, which is used to improve the optical performance of the beam splitter and ensure the accuracy of the beam splitter structural component. Next, optical simulation and optimization of multi-layer nano-scale film layers are carried out, and atomic layer deposition technology is used to deposit multi-layer nano-scale films on the surface of the beam splitter structural component. At the same time, according to the optical simulation and optimization of the multi-layer nano-scale film layers, the thickness of the multi-layer nano-scale film layers is monitored and adjusted in real time to achieve nano-scale thickness control and ensure the uniformity and high quality of the film coating. Finally, the surface of the coated beam splitter structural component is subjected to surface enhancement treatment to improve the film layer adhesion and anti-damage properties, obtaining a super-smooth beam splitter. The processing technology of the beam splitter in this application has achieved major breakthroughs in aspects such as material selection, processing precision, and surface treatment, making the surface roughness of the beam splitter better than 0.09 nm and significantly improving the optical performance of the beam splitter.

[0024] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application and should not be construed as a limitation to the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0026] The following is combined with Figure 1, a preparation method of a super-smooth spectroscope provided by this application will be described in detail.

[0027] In this embodiment, as Figure 1 shown, a preparation method of a super-smooth spectroscope provided by the present invention includes: Step S1, after mixing the pretreated nano-composite quartz material and silicon nitride, use ultrasonic-assisted nano-diamond abrasive grinding technology to grind to obtain a mixed material.

[0028] Specifically, the pretreatment includes plasma surface cleaning and surface activation treatment, which are mainly used to remove surface impurities, increase the surface energy state, and improve the material adhesion in subsequent processing and coating steps. Among them, the plasma surface cleaning is specifically: using oxygen plasma to remove surface organic pollutants and oxide layers, the gas type is O2, the treatment pressure is 70 Pa, the power is 150 W, and the treatment time is 15 minutes; the surface activation treatment is specifically: increasing the active sites on the surface through nitrogen plasma treatment to improve the material adhesion effect, the gas type is N2, the treatment pressure is 60 Pa, the power is 120 W, and the treatment time is 10 minutes. Here, using nano-composite quartz material and silicon nitride as raw materials is mainly because they have excellent mechanical strength, thermal stability and low thermal expansion coefficient, which are suitable for the processing of high-precision optical components; among them, for nano-composite quartz, its mechanical properties are enhanced by doping nano-particles, and at the same time the thermal expansion coefficient is reduced to ensure the dimensional stability of the product under various environmental conditions.

[0029] In a specific embodiment, in the ultrasonic-assisted nano-diamond abrasive grinding technology, the ultrasonic vibration is used to make the nano-diamond abrasive form a uniform grinding effect on the material surface, improving the cutting efficiency and uniformity of the abrasive. Among them, the nano-diamond abrasive is high-purity nano-diamond to ensure high hardness and high precision during the grinding process. At the same time, during the grinding process using ultrasonic-assisted nano-diamond abrasive grinding technology, the surface morphology and surface roughness of the nano-composite quartz material and silicon nitride are monitored in real time; and the surface roughness of the ground nano-composite quartz material and silicon nitride is below 1 nm. Specifically, a real-time interference measurement system and a laser confocal microscope are used to monitor the surface morphology and surface roughness to ensure the accuracy of each grinding step. It should be noted that the real-time interference measurement system uses an interferometer, which mainly measures the surface morphology, gives real-time feedback on the changes during the grinding process, and adjusts the processing parameters. The laser confocal microscope mainly measures the surface roughness with high precision to ensure the uniformity and consistency of the grinding effect.

[0030] Step S2, polish the mixed material using plasma-assisted chemical polishing technology to obtain the polished mixed material.

[0031] Specifically, the plasma-assisted chemical polishing technology specifically includes: polishing is carried out by the plasma-assisted chemical polishing technology under the action of a nanocatalyst in an environment of 20 - 60 °C; the surface roughness of the polished nano-composite quartz material and silicon nitride is ≤ 0.05 nm. Here, the plasma-assisted chemical polishing technology includes plasma and chemical polishing technology, and polishing is carried out in a low-temperature environment to reduce the influence of thermal effects on the material and avoid material deformation and performance degradation caused by thermal stress; at the same time, an environment-friendly chemical solution is used, that is, non-toxic and harmless chemical reagents are used to reduce environmental pollution, and a nanocatalyst is combined to enhance the chemical reaction rate, improve the polishing efficiency, and protect the substrate from damage, thereby improving the polishing efficiency and uniformity and ensuring the safety and environmental friendliness of the operation.

[0032] Among them, plasma-assisted chemical polishing is specifically: using plasma energy to promote chemical reactions, making the polishing process more uniform and precise, and reducing surface defects. Here, the parameters of plasma-assisted chemical polishing are: the gas type is oxygen, the processing pressure is 60 Pa, the power is 1210 W, the temperature is 20 °C (low-temperature environment), and the time is 20 minutes. The catalyst used here is niobium zirconium oxide (NbZrO x ), niobium (Nb) and zirconium (Zr) are metals with high melting points and chemical stabilities, and their oxides can provide strong electronic conductivity in catalytic reactions. NbZrO x can provide effective catalytic activity at low temperatures, contributing to surface planarization and the removal of micro-defects.

[0033] Step S3, the polished mixture is subjected to nanomachining using the femtosecond laser direct writing technology to obtain a beam splitter structural component; at the same time, the optical coherence tomography technology is used to monitor the surface topography change of the beam splitter structural component during the processing of the femtosecond laser direct writing technology in real time.

[0034] Specifically, nanomachining is carried out using the femtosecond laser direct writing technology. By precisely controlling the laser pulse time and energy, using the characteristics of femtosecond laser pulses being short and high-energy, nano-scale surface structures are precisely machined, avoiding material damage caused by the heat-affected zone and achieving high-precision surface micro-structure machining. In the femtosecond laser direct writing technology, the laser pulse time is 50 - 300 fs, and the energy is 50 - 500 nJ; and during the femtosecond laser direct writing technology process, the optical coherence tomography technology is used to monitor the surface topography change of the beam splitter structural component during the laser processing in real time to ensure the accuracy of the nanostructure. Here, OCT is used for real-time monitoring, which provides high-resolution three-dimensional imaging to monitor the changes during the processing in real time and ensure the processing accuracy. It should be noted that during the processing of the femtosecond laser direct writing technology, the micro-structure is precisely designed through computer-aided design software to ensure that it meets the optical performance requirements.

[0035] Step S4: Conduct optical simulation and optimization of the multi-layer nano-scale film layer, and use atomic layer deposition technology to deposit the multi-layer nano-scale film on the surface of the spectroscope structural component; meanwhile, monitor and adjust the thickness of the multi-layer nano-scale film layer in real time according to the optical simulation and optimization of the multi-layer nano-scale film layer.

[0036] Specifically, conducting optical simulation and optimization of the multi-layer nano-scale film layer, and using atomic layer deposition technology to deposit the multi-layer nano-scale film on the surface of the spectroscope structural component; meanwhile, monitoring and adjusting the thickness of the multi-layer nano-scale film layer in real time according to the optical simulation and optimization of the multi-layer nano-scale film layer specifically includes: First, conduct optical simulation and optimization of the refractive index matching, spectral transmittance, and reflectivity of the multi-layer nano-scale film layer; then, use atomic layer deposition technology to deposit nano-scale thin films layer by layer on the surface of the spectroscope structural component to obtain the multi-layer nano-scale film layer; meanwhile, during the processing of atomic layer deposition technology, use ellipsometry and quartz crystal microbalance to monitor the thickness of the multi-layer nano-scale film layer in real time, and dynamically adjust the process parameters of atomic layer deposition technology according to the optical simulation and optimization of the multi-layer nano-scale film layer, thereby adjusting the thickness of the multi-layer nano-scale film layer to ensure compliance with the design requirements. Among them, during the process of depositing nano-scale thin films layer by layer on the surface of the spectroscope structural component by atomic layer deposition technology, control the film layer thickness at 0.1 - 0.2 nm / cycle, and the thickness of the multi-layer nano-scale film layer is 50 - 150 nm.

[0037] When using atomic layer deposition technology for coating, through chemical adsorption and reaction, deposit thin films with an atomic level thickness of 0.1 - 0.2 nm / cycle layer by layer to achieve nano-scale thickness control and ensure the uniformity and high quality of the coating. It should be noted that specifically, conducting optical simulation and optimization of the multi-layer nano-scale film layer first is: using the film layer design software TF Calc to predict the film layer performance and optimize the film layer design, that is, conduct optical simulation and optimization of the refractive index matching, spectral transmittance, and reflectivity of the multi-layer nano-scale film layer, and utilize the optical properties of different materials to achieve high light transmittance and precise spectral splitting ratio, ensure the precise control of the thickness and refractive index of each layer of the film, and thus ensure the best optical properties. Using atomic layer deposition technology to deposit nano-scale thin films layer by layer on the surface of the spectroscope structural component to obtain the multi-layer nano-scale film layer specifically is: using materials such as TiO2 / Al2O3 / SiO2, and utilizing the atomic layer deposition alternating gas phase adsorption mechanism to control the film layer thickness at 0.1 - 0.2 nm / cycle, thereby obtaining the multi-layer nano-scale film layer.

[0038] Step S5: Perform surface enhancement treatment on the coated spectroscope structural component to obtain an ultra-smooth spectroscope.

[0039] Specifically, the surface enhancement treatment includes: treating the surface of the coated spectroscopic mirror structural member after coating by using high-energy ion beam technology and laser annealing technology to further improve the adhesion and damage resistance of the film layer. Among them, the high-energy ion beam technology specifically is: by treating with high-energy ion beams, the density and surface hardness of the film layer are increased, and the durability of the film layer is improved. It should be noted that during the surface enhancement treatment process, an atomic force microscope and an optical profiler are used for multi-point detection to ensure that the surface roughness and optical performance meet the expected standards. Among them, the main function of the atomic force microscope is to detect the surface roughness with high resolution to ensure the surface quality; the main function of the optical profiler is to perform three-dimensional surface topography measurement to verify the consistency and accuracy of the surface topography. This design is for the special requirements of the ultra-smooth spectroscopic mirror.

[0040] In this application, the method for preparing the ultra-smooth spectroscopic mirror further includes: During the process of step S1-step S5, the preparation process of each step is monitored in real time, and the defects occurring in the corresponding steps are timely fed back, and then automatic correction is realized.

[0041] Specifically, by using a full-automatic detection system, a real-time feedback mechanism, and an automatic correction system, real-time detection and automatic correction of the defects occurring during the processing are realized. Among them, the full-automatic detection system specifically is: using advanced OCT and three-dimensional profile scanning technologies to provide high-resolution surface topography and internal structure detection; the real-time feedback mechanism specifically is: using sensors and monitoring systems to obtain processing data in real time, and performing data analysis and optimization to ensure the quality consistency and stability of the product. Here, the role of data analysis is: combining AI big data technology, analyzing historical data, continuously improving and optimizing the processing process, and improving efficiency and accuracy; at the same time, manual review feedback is also used: high-precision surface measurement data (such as AFM) is uploaded to the monitoring system for review by engineers. The automatic correction system specifically is: using the detection data fed back in real time to immediately correct the defects occurring during the processing, and improving the processing accuracy and efficiency.

[0042] This application also proposes an ultra-smooth spectroscopic mirror, which is prepared by the above method for preparing the ultra-smooth spectroscopic mirror.

[0043] The super-smooth spectroscope prepared by the preparation method of the super-smooth spectroscope of the present application is simulated. Specifically, under the parameter conditions of the above steps S1 and S2, the surface roughness of the polished nano-composite quartz material and silicon nitride is 0.03 nm; in steps S3 and S4, the laser pulse time in the femtosecond laser direct writing technology is 100 fs, and the energy is 150 nJ. The atomic layer deposition technology is used for coating. Through chemical adsorption and reaction, a film with a thickness of 0.1 nm at the atomic level is deposited layer by layer, and the thickness of the obtained multi-layer nano-scale film layer is 60 nm; in step S5, the surface of the coated spectroscope structure is enhanced to obtain a super-smooth spectroscope. Its physical diagram and surface profile diagram are as Figure 3 and 4 shown. Substituting the indexes of the obtained super-smooth spectroscope into the simulation, the obtained results are as Figure 2 shown. It can be concluded that the simulation result is: when a 1W laser is incident, the surface scattering of the super-smooth spectroscope is 3.8×10^-10W, meeting the test requirements of the 10^-10 order of magnitude for the backscattering of the telescope.

[0044] At the same time, the roughness of the above super-smooth spectroscope is characterized, as Figure 5 shown. It can be concluded that the actual roughness of the super-smooth spectroscope is 0.088 nm.

[0045] Here, those skilled in the art can understand that the specific operations in the above super-smooth spectroscope have been described in detail in the description of the preparation method of the super-smooth spectroscope with reference to Figures 1 to 5 above. Therefore, the repeated description thereof will be omitted.

[0046] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. Any equivalent structural changes made by using the description of the specification and drawings of the present invention shall be included in the protection scope of the present invention by the same token.

Claims

1. A method for preparing an ultra-smooth beam splitter, characterized in that: The following steps are involved: Step S1, mixing the pretreated nanocomposite quartz material and silicon nitride, and grinding them using an ultrasonic-assisted nanodiamond abrasive grinding technology to obtain a mixed material; Step S2, polishing the mixture using a plasma-assisted chemical polishing technique to obtain a polished mixture; Step S3, nano-processing the polished mixture using a femtosecond laser direct writing technique to obtain a spectroscope structure; and simultaneously, using an optical coherence tomography technique to monitor in real time the surface morphology changes of the spectroscope structure during the processing using the femtosecond laser direct writing technique; Step S4, performing optical simulation and optimization of the multi-layer nano-scale film layer, and using atomic layer deposition technology to perform multi-layer nano-scale coating on the surface of the spectroscope structure; at the same time, monitoring and adjusting the thickness of the multi-layer nano-scale film layer in real time according to the optical simulation and optimization of the multi-layer nano-scale film layer; Step S5, performing surface enhancement treatment on the coated beam splitter structure to obtain an ultra-smooth beam splitter.

2. The method for preparing an ultra-smooth beam splitter according to claim 1, characterized in that: In step S1, during the grinding process using the ultrasonic-assisted nano-diamond abrasive grinding technology, the surface morphology and surface roughness of the nano-composite quartz material and silicon nitride are monitored in real time; and the surface roughness of the nano-composite quartz material and silicon nitride after grinding is below 1 nm.

3. The method for preparing an ultra-smooth beam splitter according to claim 1, characterized in that: In step S2, the plasma assisted chemical polishing technology specifically includes: Polishing is performed by plasma-assisted chemical polishing technology under the action of nano-catalysts at 20-60°C; the surface roughness of the polished nano-composite quartz material and silicon nitride is ≤0.05 nm.

4. The method for preparing an ultra-smooth beam splitter according to claim 1, characterized in that: In step S3, in the femtosecond laser direct writing technology, the laser pulse time is 50-300 fs and the energy is 50-500 nJ.

5. The method for preparing an ultra-smooth beam splitter according to claim 1, characterized in that: In step S4, the optical simulation and optimization of the multi-layer nano-scale film layer are performed, and the multi-layer nano-scale coating is performed on the surface of the spectroscope structure by using the atomic layer deposition technology; at the same time, the thickness of the multi-layer nano-scale film layer is monitored and adjusted in real time according to the optical simulation and optimization of the multi-layer nano-scale film layer, specifically including: First, the refractive index matching, spectral transmittance and reflectivity of the multi-layer nanoscale film layer are optically simulated and optimized. Then, the atomic layer deposition technology is used to deposit nanoscale thin films layer by layer on the surface of the spectroscope structure to obtain the multi-layer nanoscale film layer. At the same time, during the atomic layer deposition process, ellipsometry and quartz crystal microbalance are used to monitor the thickness of the multi-layer nanoscale film layer in real time, and according to the optical simulation and optimization of the multi-layer nanoscale film layer, the process parameters of the atomic layer deposition technology are dynamically adjusted to adjust the thickness of the multi-layer nanoscale film layer.

6. The method for preparing an ultra-smooth beam splitter according to claim 5, characterized in that: The atomic layer deposition technology controls the film thickness to be 0.1-0.2 nm / cycle during the process of depositing nano-scale thin films layer by layer on the surface of the spectroscope structure, and the thickness of the multi-layer nano-scale film is 50-150 nm.

7. The method for preparing an ultra-smooth beam splitter according to claim 1, characterized in that: In step S5, the surface enhancement treatment includes: The surface of the coated spectroscope structure is processed by high energy ion beam technology and laser annealing technology.

8. The method for preparing an ultra-smooth beam splitter according to claim 1, characterized in that: The preparation method further comprises: During the process of step S1 to step S5, the preparation process of each step is monitored in real time, and the defects occurring in the corresponding step are fed back in time, thereby achieving automatic correction.

9. The method for preparing an ultra-smooth beam splitter according to claim 1, characterized in that: In step S1, the pretreatment includes plasma surface cleaning and surface activation treatment.

10. An ultra-smooth beam splitter, characterized in that: The ultra-smooth beam splitter is prepared by the method for preparing the ultra-smooth beam splitter described in any one of claims 1 to 9.

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