In recent years, work on chemically vapor-deposited zinc sulfide (CVD ZnS) has resulted in the development of a material that shows much promise for infrared systems applications involving windows (or domes) and operating in the 8- to 12-μm region. This paper summarizes measurements and calculations carried out in the context of assessing relevant features of CVD ZnS, particularly with regard to: (a) Spectral Transmittance /Emittance. We show that CVD-ZnS windows capable of satisfying structural requirements stemming from the mechanics of high-speed flight exhibit transmittance and emittance characteristics which do not seriously affect the system sensitivity, over the range of anticipated thermal loads. And (b) Image Spoiling Properties. Line-spread function data demonstrate that small-angle scattering, index inhomogeneities, and other potential image-spoiling features do not inject any detectable degradation in system MTF, at spatial frequencies of interest for high-resolution thermal imaging.

Date Published: 27 February 1980
PDF: 10 pages
Proc. SPIE 0204, Physical Properties of Optical Materials, (27 February 1980); doi: 10.1117/12.958150

Published in SPIE Proceedings Vol. 0204:
Physical Properties of Optical Materials
Roy F. Potter, Editor(s)