The 86 papers in this collection cover the latest developments in the field of thermal and photon IR detectors, with an emphasis on thermal detectors. The companion 1992 Milestone volume MS66, "Selected Papers on Semiconductor Infrared Detectors," covered only photon detectors. The developments covered in this volume are directed toward improving the performance of single-element devices and large electronically scanned arrays, enabling IR detectors to operate at higher temperatures, and making IR detectors cheaper and more convenient to use.