Photoacoustic gas detection with LED QEPAS

Various configurations and applications have been investigated and realized since the pioneering introduction of quartz-enhanced photoacoustic spectroscopy (QEPAS) by Kosterev et al. in 2002. However, the required submillimeter diameter of the acoustic resonator demands an excellent beam quality of laser source and precise adjustments of the QEPAS system. In a new approach, the off-beam resonator scheme is proposed for avoiding these demands of conventional QEPAS systems.