An Ebert-Fastie spectrometer and a filter radiometer for a cryogenically cooled IR-sensor of the Infrared Background Signature Survey experiment are described. The spectrometer covers the spectral range from 2.5 to 22.6 microns with a resolving power of greater than 300 and uses Si:IN, Si:Bi, and Si:As detectors. The radiometer is based on 29 detector elements of different size made from Si:In material. The light is modulated by two tuning fork choppers at 238 Hz, which can be switched on within 0.5 sec. The detector signals are digitized and a digital signal processor performs synchronous rectification and integration for up to 16 channels simultaneously providing amplitude and phase for each detector.

Date Published: 1 November 1990
PDF: 14 pages
Proc. SPIE 1340, Cryogenic Optical Systems and Instruments IV, (1 November 1990); doi: 10.1117/12.23047

Published in SPIE Proceedings Vol. 1340:
Cryogenic Optical Systems and Instruments IV
Ramsey K. Melugin; Gerald R. Pruitt, Editor(s)