A superconducting transition edge bolometer

Liquid helium temperature bolometers are widely used as detectors of broadband infrared and far-infrared radiation. Although most presently-used bolometers are made from semiconductors, superconducting bolometers, operated on the resistive transition, have been studied for many years. Previous superconducting bolometers suffered from appreciable excess low-frequency noise. The recent discovery that this low frequency noise can be greatly reduced if the film is strongly thermally coupled to its substrate has re-opened the possibility of making very sensitive superconducting bolometers. In this article the authors briefly describe a superconducting bolometer which is designed around an Al transition-edge thermometer on a sapphire substrate. (Auth.)