Ultrasensitive detection of trace gases with diode lasers by frequency modulation spectroscopy

摘要

Abstract: Frequency modulation spectroscopy (FMS) with mid- and near- infrared tunable diode lasers is an attractive approach for a number of applications that require ultrasensitive detection of trace gases. The technique combines high detection sensitivity with high detection speed and is capable of detecting numerous small molecular weight compounds at levels ranging from low parts-per-million to sub-parts-per-billion. We will review the principles of FMS and discuss its application in areas relevant to materials processing.!8