Optical coating element surface shape compensation method based on mixture single-layer film

Abstract

The invention discloses an optical coating element surface shape compensation method based on a mixture single-layer film. An ion beam auxiliary mixture single-layer film is deposited on a non-coatingsurface of a substrate or a surface to be coated with a concave surface shape after coating by using an electron beam double-source co-evaporation technology and an ion beam auxiliary deposition technology at the same time, and an optical dummy layer with the same refractive index as the substrate is formed to tune the surface shape of a coating element. According to the method, surface shape compensation can be carried out on the coating element deposited on the substrate with any refractive index, the quality reduction of the wave surface caused by coating is reduced, the spectral performance of the coating element is not influenced, and the method is suitable for single-sided coating elements and double-sided coating elements.

Description

technical field [0001] The invention relates to an optical thin film, in particular to a method for compensating the surface shape of an optical coating element based on a mixture monolayer film. Background technique [0002] Wavefront quality is one of the performance parameters of optical thin-film components, and the wavefront quality of thin-film components will affect the beam output quality of laser devices. The intrinsic stress of the film layer will cause the wavefront quality of the coated component to change after coating, and the surface shape compensation technology is an effective technical way to improve the wavefront quality of the coated component. The surface shape compensation technology currently used includes substrate pre-surface shape technology and film layer stress compensation technology. The substrate pre-surface shape technology processes the substrate into the opposite surface shape according to the surface shape change caused by the film layer. ...

AI Technical Summary

Problems solved by technology

[0004] One is to coat a silicon dioxide film layer on the non-coated surface of the substrate to offset the stress on the functional film surface. This compensation technology is only applicable to substrates with a refractive index close to that of silicon dioxide materials, such as fused silica substrates;

[0005] The second is to coat the same film layer on both sides of the substrate. This method increases the coating cost and is not suitable for thin-film components that require different technical indicators on both sides of the substrate;

[0006] The third is to use different deposition techniques to prepare high and low refractive index layers, such as the use of atomic layer deposition technology to prepare Al 2 o 3 , prepared SiO by ion beam sputtering 2 layer (see Applied Surface Science, 2019, 476:521-527), this method needs to replace the coating equipment every time a layer of film is prepared, and the actual preparation process is extremely difficult

Images