Baffle plate design method for controlling membrane thickness distribution of spherical optical element in coating machine planet system

Abstract

The invention discloses a baffle plate design method for controlling membrane thickness distribution of a spherical optical element in a coating machine planet system. In a vacuum coating process, a membrane material is transmitted in a vacuum environment in an evaporation or sputtering mode, and a membrane of which thickness distribution is not uniform is formed on the surface of the spherical optical element. Membrane thickness distribution models capable of actually reflecting thickness distributions of membranes deposited on the spherical optical element in the vacuum coating machine planet system when a baffle plate is not used and when the baffle plate is used for correction are respectively established. According to the membrane thickness distribution model when the baffle plate is not used, evaporating or sputtering characteristics of the membrane material are determined in the vacuum coating process; and then based on the characteristics, the membrane thickness distribution model when the baffle plate is used for correction is used to theoretically simulate the membrane thickness distribution on the spherical optical element in the vacuum coating machine planet system. The baffle plate design is optimized through a computer until the membrane thickness distribution on the spherical optical element in the vacuum coating machine planet system, which is corrected by the baffle plate, reaches the design demand, and thus the optimal baffle plate design is obtained. Compared with the traditional baffle plate design method, the baffle plate design method provided by the invention has the advantage that the baffle plate design is optimized by using the computer, so that the accurate control of the membrane thickness distribution on the spherical optical element can be realized.

Description

technical field [0001] The invention relates to the field of optical thin film element preparation, in particular to a baffle design method for controlling the film thickness distribution of spherical optical elements in a coating machine planetary system. Background technique [0002] The design of the optical system is becoming more and more sophisticated. In order to meet the performance indicators of the optical system, spherical optical elements are used in some optical systems, and special designed optical films are coated on the surface of the spherical optical elements to improve the performance of the spherical optical elements. The current techniques for preparing optical thin films on spherical optical elements can be mainly divided into physical vapor deposition (PVD) and chemical vapor deposition (CVD). Physical vapor deposition is a process in which a thin film is deposited on the surface of a spherical optical element by evaporating or sputtering a thin film m...

AI Technical Summary

Problems solved by technology

[0005] As far as the planetary system of the vacuum coating machine is concerned, since the planetary revolution / rotation can be flexibly adjusted, the randomness of the position of any point on the coating surface of the spherical optical element is very high, so that any point on the coating surface of the spherical optical element is closely related to the surface of the evaporation or sputtering source. The projection trajectory of the connection line of any point on the plane where the baffle is placed is very complicated, which makes it difficult to have an analytical solution for the design of the baffle

The traditional baffle design method used to control the film thickness distribution on the optical element in the planetary system of the vacuum coating machine mainly relies on the coating experience and repeatedly modifies the baffle design through a large number of process experiments to meet the specific film thickness distribution. The process is very long, and generally requires at least several or even dozens of experiments

Images