This paper is the first of two papers reviewing a conference on infrared detectors (IRD) held by the SPIE at San Diego, California in August 1983. This first paper surveys elemental infrared detectors, both thermal and photon, and discusses some applications. Among the detectors discussed in this paper are the following: Thermistor IRD, Lead-salt IRD (PbS and PbSe), Indium antimonide IRD, Mercury cadmium telluride IRD, Silicon extrinsic IRD and Schottky-diode-based IR sensors.