Optical properties of evaporated films of ZnS in the vacuum ultraviolet from 160 to 2000 A

Abstract

The optical properties of vacuum evaporated films of ZnS have been measured from 160 to 2000 A. The reflectance spectrum shows three maxima, at 1800, 1250, and 900 A. The first two are associated with interband transitions while the third is more of an atomic transition. To shorter wavelengths, the reflectance spectrum is featureless and drops to very low values as the wavelength decreases to 300 A. Possible applications of ZnS films in making reflecting interference filters consisting of alternating layers of high- and low-extinction coefficient materials is discussed for wavelengths less than 600 A.