Corner cube prism-enhanced photoacoustic spectroscopy based gas sensing

A corner cube prism-enhanced photoacoustic spectroscopy (PAS) based trace gas sensor was demonstrated for the first time. A corner cube prism was used to reflect the laser beam to pass through the photoacoustic (PA) cell for two times. With the enhanced absorption, the PAS signal had a 1.49 times improvement compared to the sensor system without the prism. A minimum detection limit (MDL) of 1.48 ppm for the detection of acetylene (C₂H₂) was obtained. Furthermore, corner cube prim has a merit that the reflected beam is always parallel to the incident beam. Therefore, the PAS signal was measured with different rotation and pitch angels of the prism. The measured results indicated that such sensor system had an excellent signal stability and therefore is advantageous for field application.