The Infra-Red Sensitivity of Superconducting Bolometers

Columbium nitride superconducting bolometers have been studied for sensitivity when irradiated with a wide band of modulated infra-red radiation of about 0.1 microwatt/mm2 intensity. The bolometer response was amplified by means of a matching input transformer and wide-band amplifier. Time constants for different bolometers ranging from 0.7 to 17.0 milliseconds were observed. Comparisons are given between these superconducting bolometers and other infra-red detectors described in the literature on the basis of reference conditions suggested by Jones (reference 1). Of the 25 superconducting bolometers studied in detail the 9 most sensitive had figures of merit ranging from 14.0 to 1.3.