Optical Properties of Magnesium Fluoride Films

Abstract

Transmittance and reflectance of magnesium fluoride films deposited on optical glass and fused quartz are measured as functions of wavelength between 3500Å and 6000Å. Film deposited on fused quartz kept above 240°C shows remarkable scattering as compared with that of film deposited on optical glass under the same condition. This difference is explained by the affinity of film to substrate surface. Index of refraction is determined from wavelength of refraction of determined from wavelength of transmittance extremes and film-thickness. The aging effect can not be observed. The causes of porosity of films are discussed.