Baffle design method for controlling film thickness distribution of ellipsoidal optical element

Abstract

The invention discloses a baffle design method for controlling the film thickness distribution of an ellipsoidal optical element. A film material is transported in the vacuum coating process in a vacuum environment by evaporation or sputtering, and forms a film with non-uniform thickness distribution on the surface of the ellipsoidal optical element. Film thickness distribution models which can truly reflect the thickness distribution of the film deposited on the ellipsoidal optical element in the vacuum coating process when a baffle is not used and when the baffle is used for correction are respectively established. The evaporation or sputtering characteristics of the film material in the vacuum coating process are determined according to the film thickness distribution model when the baffle is not used; and on that basis, the film thickness distribution model when the baffle plate is used for correction is used for theoretically simulating the thickness distribution of the film deposited on the ellipsoidal optical element in the vacuum coating process. The baffle design is optimized by a computer until the film thickness distribution on the ellipsoidal optical element reaches thedesign requirements after the baffle is corrected; the optimal baffle design is obtained; and the precise control of the film thickness distribution on the ellipsoidal 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 an ellipsoidal optical element. 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, some optical systems use ellipsoidal optical elements, and special designed optical films are plated on the surface of the ellipsoidal optical elements to improve the performance of the ellipsoidal optical elements. The current techniques for preparing optical thin films on ellipsoidal 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 an ellipsoidal optical element by evaporating or sputtering a thin film material under vacuum conditions...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is: to overcome the deficiencies of the existing film thickness distribution model when the baffle is not used and the baffle design method for controlling the film thickness distribution on the ellipsoidal optical element in the vacuum coating process, respectively establish a real Reflect the thickness distribution model of the film deposited on the ellipsoidal optical element during the vacuum coating process without using the baffle and with the correction of the baffle, and provide an optimal design method of the baffle for controlling the thickness distribution of the film on the ellipsoidal optical element , to achieve precise control of film thickness distribution on ellipsoidal optical elements

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