High Purity ZnS/Ge Interference Filter Emittance

摘要

Data are presented that demonstrate infrared thin film interference filters made with CVD zinc sulfide start materials exhibit significantly higher spectral emittance than those made with IRTRAN II. A simple radiometric model and comparative analysis are discussed that indicates elevated filter emittance levels may adversely impact infrared sensors and seekers designed to operate in the 7 - 15 micron region. It is expected that systems that incorporate filters made with CVD ZnS could exhibit anomalous high backgrounds, image blurring or optical cross talk.