Simultaneous exhaled carbonyl sulfide (OCS) and carbon dioxide concentration measurements in human breath are demonstrated with a compact pulsed quantum-cascade laser-based gas sensor. We achieved a noise-equivalent sensitivity (1σ) of 1.2 parts per billion by measuring a well-isolated OCS P(11) absorption line in the ν3 band at 2057.6 cm-1 using an astigmatic Herriott cell of 36-m optical path length and 0.4-s acquisition time.
© 2004 Optical Society of America
Original Manuscript: March 19, 2004
Revised Manuscript: July 12, 2004
Published: November 10, 2004
Gerard Wysocki, Matt McCurdy, Stephen So, Damien Weidmann, Chad Roller, Robert F. Curl, and Frank K. Tittel, "Pulsed quantum-cascade laser-based sensor for trace-gas detection of carbonyl sulfide," Appl. Opt. 43, 6040-6046 (2004)