We present the application of a compact setup for real-time <i>in situ</i> trace-gas detection based on photothermal beam deflection (mirage-effect) spectroscopy to environmental monitoring and chemical analysis. The setup provides many advantages for local (nonremote) detection applications, such as rapid response and high sensitivity under true <i>in situ</i> conditions. The detection limit of C<sub>2</sub>H<sub>4</sub> in open air is estimated to be 0.25 parts in 10<sup>9</sup>, based on concentration calibration with the dominant noise that is due to atmospheric turbulence on a time scale of 1 s. Detection limits are extrapolated for other species, and applications are explored by real-time measurements of gas emissions from a variety of solid and semisolid samples.
© 1997 Optical Society of America
Bob L. Zimering and A. Claude Boccara, "Applications of a compact photothermal-deflection-based setup for trace-gas detection in real-time in situ environmental monitoring and chemical analysis," Appl. Opt. 36, 3188-3194 (1997)