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CN-116400440-B - Multi-material surface-type controllable millimeter-scale lens and preparation method thereof

CN116400440BCN 116400440 BCN116400440 BCN 116400440BCN-116400440-B

Abstract

The invention discloses a multi-material surface-type controllable millimeter-scale lens and a preparation method thereof, belonging to the technical field of laser micro-nano processing, the invention adopts a method of oblique incidence of two ion beams to bombard the surface of a hard material sample, the sample is held on a sample holder and rotated uniformly at a speed and etched for a period of time to provide a very smooth millimeter-scale lens. The millimeter-scale lens provided by the invention is also very suitable for use as a template to transcribe millimeter-scale convex lenses due to its excellent stability and surface quality. In a word, the method for obliquely incident two ion beams can be used for etching smooth and uniform millimeter-scale lenses with controllable surface types on the surfaces of various hard materials at last, and the problems of difficult surface morphology control, poor surface quality, low preparation efficiency, complex preparation process and the like in millimeter-scale lens preparation are solved to a certain extent.

Inventors

  • LIU XUEQING
  • QI JINYONG
  • CHEN QIDAI
  • SUN HONGBO

Assignees

  • 吉林大学

Dates

Publication Date
20260505
Application Date
20230413

Claims (6)

  1. 1. The preparation method of the multi-material surface-type controllable millimeter-scale lens is characterized by comprising the following steps of: Step one, treating a sample to be processed; Sequentially wiping a substrate to be processed by using cotton balls dipped with an acetone solution and an ethanol solution, washing by using deionized water and drying by using a low-temperature oven, so as to remove the residual pollutants on the surface of the substrate, taking out the substrate for standby, and preparing a sample; Step two, preparing a millimeter-sized lens by utilizing oblique incidence etching of two ion beams; Firstly, fixing a prepared sample on a sample holder, vacuumizing to remove air influence, etching by adopting two ion beams in an oblique incidence method, before etching, firstly adjusting the height of the sample holder to be the ion beam converging position, and then adjusting the height of the sample holder upwards or downwards to ensure that the two ion beams are incompletely converged on the surface of a substrate to be processed or separated to a certain extent after converging; In the second step, two ion beams are adopted to make oblique incidence at symmetrical angles.
  2. 2. The method of claim 1, wherein the substrate to be processed in the first step comprises a transparent hard optical material of fused silica, sapphire or diamond, the substrate has a size of 3mm-20mm, a thickness of 100 μm-1mm, and a low temperature oven temperature of 50 ℃ to 100 ℃.
  3. 3. The method of claim 1, wherein the ion beam in the second step is generated by ionized argon, the working voltage of the instrument is 0.1-6kV, the etching time is 0-100 hours, the incident angle of the two ion beams is 0-10 °, the focusing degree of the ion beams is 0-100%, the sample holder for fixing the sample is rotated at a constant speed of 360 ° or is rotated by swinging back and forth in a specific angle range, and the rotation speed is 1-6 revolutions per minute.
  4. 4. The method of claim 1, wherein the sample holder is adjusted up or down to a height of 10 μm to 1000 μm.
  5. 5. A method of producing a multi-material planar controllable millimeter-scale lens as defined in claim 1, and step two, etching by three or more ion beams to obtain the millimeter-sized lens structure.
  6. 6. A multi-material surface-type controllable millimeter-scale lens, characterized by being obtained by the production method according to any one of claims 1 to 5.

Description

Multi-material surface-type controllable millimeter-scale lens and preparation method thereof Technical Field The invention belongs to the technical field of laser micro-nano processing, and particularly relates to a high-efficiency preparation method for realizing a millimeter-scale concave lens with a controllable surface on the surface of different hard materials by utilizing an ion beam etching technology. The two ion beams are converged and obliquely incident to the surfaces of different hard materials, so that the uniform millimeter-scale concave lens with controllable surface shape can be efficiently etched and prepared. Background With the advancement of science and technology, the trend of modern optical systems is miniaturization and integration, which requires the optical system to be reduced in size from the centimeter level to the millimeter and micrometer level. Millimeter-scale lenses and micrometer-scale microlenses have been widely studied by researchers as extremely important fundamental elements in modern integrated optics. The lens surface type can be divided into sphere and aspheric surface, and the mathematical expression of axisymmetric aspheric surface type is commonly usedThe Y axis is the system optical axis, x is the abscissa value of each point of the system, c is the curvature of the lens vertex, k is the conical coefficient of the aspheric surface, and is also a key parameter for determining the lens surface, and the surface shape can be divided into five types of hyperboloid, paraboloid, ellipse, circle and flat ellipse according to the difference of the k value of the conical coefficient. Besides the general spherical surface type, various aspherical surface type lenses have various peculiar advantages, such as hyperboloid type lenses are mainly used for reflection and telescopic systems, parabolic type lenses are mainly used for off-axis telescopic systems, and elliptical type lenses are mainly used for laser collimation instruments and the like. Many methods for preparing micro lenses, such as photolithography, nanoimprint, etching assisted with femtosecond laser processing, etc., have been developed, but the application of these methods to millimeter-scale lenses has problems of difficult or impossible preparation. The preparation of millimeter-scale lenses on the surfaces of various hard materials to meet the use requirements of optical systems also faces problems such as difficult surface morphology control, poor surface quality, low preparation efficiency, complex preparation process and the like. Currently, the mainstream methods for preparing millimeter-scale lenses can be simply divided into the following categories: 1. the micro-processing means such as injection molding, namely, the injection molding is to press colloid into a template by pressure to prepare a structure, the use method is simple, the efficiency can be ensured, but the template is difficult to prepare, the surface quality is poor, and the use of the template is limited by the defects of inapplicability to hard materials and the like; 2. the diamond turning method is to utilize the single point turning of the diamond tool to process the optical part meeting the optical quality requirement, the surface shape is basically controllable, is relatively suitable for processing the material with lower hardness such as nonmetal, but the problems of processing efficiency, quality of the processing surface, etc. restrict the popularization of the technology; 3. The ion beam direct etching method refers to the method of directly utilizing high-energy ion beam to bombard the surface of a sample to enable material atoms to be sputtered, so that the aim of etching is achieved, the preparation precision is higher, the surface quality is good, but the ion beam is generally used for vertically bombarding and etching micro-scale micro-lenses at present, spherical lenses can be etched by theoretically increasing the etching time, but the etching efficiency is low, and the lens surface type is difficult to control. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a high-efficiency preparation method of a multi-material surface-type controllable millimeter-scale lens. Bombarding the surface of a hard material sample by adopting a method of oblique incidence of two ion beams, fixing the sample on a sample support, uniformly rotating the sample at a certain speed, and etching for a period of time to obtain a very smooth millimeter-scale lens. Compared with the conventional ion beam normal incidence, the ion beam oblique incidence method can greatly improve the etching efficiency of the ion beam, and when the included angle between the ion beam and the sample is about 10-20 degrees, the ion beam has the highest etching efficiency, namely, compared with the normal incidence, the ion beam oblique incidence method has improved efficiency. However, the ion beam oblique incidence can