A trace concentration of SO<sub>2</sub> near 225.7 nm has been detected with a master-oscillator power-oscillator laser system for the first time, to our knowledge. A photoacoustic absorption spectrum of SO<sub>2</sub> has been recorded on the <sup>1</sup><i>A</i><sub>2</sub>–<sup>1</sup><i>B</i><sub>2</sub> (π–π*) transition. Parametric dependence of the photoacoustic signal has been investigated. A detection limit (signal-to-noise ratio of 1) of 1.3 parts in 10<sup>9</sup> [1.3 ppbv (parts per billion by volume)] for SO<sub>2</sub> have been determined at 1 atmospheric pressure inside a photoacoustic cell.
© 2001 Optical Society of America
(070.1060) Fourier optics and signal processing : Acousto-optical signal processing
(280.1120) Remote sensing and sensors : Air pollution monitoring
(300.6430) Spectroscopy : Spectroscopy, photothermal
Mohammed A. Gondal and Joseph Mastromarino, "Pulsed Laser Photoacoustic Detection of SO2 Near 225.7 nm," Appl. Opt. 40, 2010-2016 (2001)