Compact Broadly-Tunable UV OPO for Trace Detection Using REMPI Mass-Spectrometry

摘要

A compact tunable UV OPO laser system has been used for the real-time detection of aromatic hydrocarbon hazardous air pollution vapors at sub-ppb levels using the jet-REMPI (jet-cooled Resonance Enhanced Multi-Photon Ionization) technique. By combining spectral and molecular mass detection, this technique provides high chemical selectivity, allowing species identification even during direct sampling of complex real-world samples. The inherent sensitivity of the jet-REMPI also allows direct real-time detection of trace species without pre-concentration. However, applications of the technique have been confined to the laboratory, requiring a complex and delicate tunable UV laser source and mass spectrometer. The results of applying a less complex, compact low-resolution OPO laser system are presented, with the goal of furthering the development a complete compact jet-REMPI instrument.