Infrared tunable diode lasers were developed in the 1960s and have been a valuable radiation source for high resolution laboratory and in situ spectroscopy. Use of Pb-salt Tunable Diode Lasers (TDL) in heterodyne applications impose stringent requirements on the TDL not normally required for laboratory spectroscopy. A review will be made of progress associated with TDLs in such heterodyne applications. Areas addressed will include such items as lifetime, operating temperature, and factors affecting excess noise. The review will emphasize the experience at Langley Research Center, but will include material from other users. The Langley information will include a description and current status of the Laser Heterodyne Spectrometer experiment and atmospheric solar absorption data obtained from a groundbased heterodyne system.
Barry D. Sidney,
"Heterodyne Applications Of Tunable Semiconductor Diode Lasers", Proc. SPIE 0415, Coherent Infrared Radar Systems and Applications II, (13 December 1983); doi: 10.1117/12.935904; https://doi.org/10.1117/12.935904