A Bandpass Filter System for Far-Infrared Radiation Measurements

Abstract

A simple bandpass filter system that is suitable to resolve the radiation emitted by far‐infrared (4–0.1 mm wavelength) source that has a relatively flat emission spectrum is described. This system, which has a resolving power of 2, an insertion loss of 3 dB, and an acceptance angle of 7°, was used in conjunction with a cooled InSb detector to measure the temperature vs wavelength characteristics of a mercury arc lamp from 4 to 0.3 mm.