BOLOMETERS FOR INFRARED AND MILLIMETER WAVES

This review describes bolometric detectors for infrared and millimeter waves. The introduction sketches the history of modem bolometers, ind icates how they fit into the more general class of thermal detectors, and describes the types of applications for which they are the optimum solution. Section I is a tutorial introduction to the elementary theo ries of bolometer response, of thermal radiation, and of bolometer noi se. Important results are derived from the laws of thermal physics in the simplest possible way. The more rigorous theories of bolometer res ponse and noise that are required for quantitative understanding and o ptimization are then summarized. This material is intended to provide the background required by workers who wish to choose the appropriate bolometer technology for a given measurement, or to evaluate a novel t echnology. Section II, then describes the various components of an eff icient bolometer and gives details of the fabrication and performance of modem bolometers. This discussion focuses on composite bolometers w ith semiconducting thermometers for operation at and below liquid heli um temperatures. The tradeoffs involved in using superconducting therm ometers at low temperatures are discussed. Finally, a discussion is gi ven of bolometers for operation at liquid nitrogen temperature which u se the new high-T(c) superconductors as thermometers.