Diode Laser Heterodyne Spectroscopy of Sulfur Dioxide

Abstract

The use of a HgCdTe photomixer well beyond its 1.2 GHz bandwidth in conjunction with a tunable diode laser has permitted the rapid, precise and accurate frequency measurement of many Doppler-limited infrared. (IR) absorptions lying within ±9 GHz of a CO2 laser emission. With care, IR line centers may be determined to within ±3 MHz. A schematic of the apparatus appears in Fig. 1.