Far infrared filters for the GALILEO-Jupiter and other missions

Seeley, J.S., Hunneman, R. and Whatley, A. (1981) Far infrared filters for the GALILEO-Jupiter and other missions. Applied Optics, 20 (1). pp. 31-39. ISSN 0003-6935 doi: 10.1364/AO.20.000031

Abstract/Summary

Extrapolation of PbTe/II-VI multilayer interference-filter technique from 20 to beyond 40µm is described and PbTe transparency reviewed; improvements below 20µm are reported. A composite filter cutting on steeply at 40µm is described that uses absorptive films of ZnS and As2S3, thin Quartz, and supplementary multilayer interference. Absorptive filters are described containing the II-VI compounds since these are found transparent at wavelengths shorter and longer than their reststrahl.