1O MU-M LASER HETERODYNE SPECTROMETER FOR REMOTE DETECTION OF TRACE GASES

Infrared heterodyne spectroscopy provides a means of measuring the intensity profiles of individual rotation-vibration spectral lines with high sensitivity. Considerable effort has been expended on optimizing these instruments for remote measurements of gases in planetary atmospheres with the result that present generation spectrometers now are beginning to provide new and startling results on the planets. The fundamental principles of laser heterodyne spectroscopy are discussed. The optical and electronic design of the spectral line receiver is considered. Representative results obtained with the spectrometer are discussed, including precision frequency measurements of MH//3 ( nu //2) lines, detection of auroral emission from Jupiter, and measurements of terrestrial O//3 and CO//2.