We report the first application of a thermoelectrically cooled, distributed-feedback quantum-cascade laser for continuous spectroscopic monitoring of CO in ambient air at a wavelength of 4.6 μm. A noise-equivalent detection limit of 12 parts per billion was demonstrated experimentally with a 102-cm optical pathlength and a 2.5-min data acquisition time at a 10-kHz pulsed-laser repetition rate. This sensitivity corresponds to a standard error in fractional absorbance of 3 × 10−5.
© 2002 Optical Society of America
[Optical Society of America ]
Anatoliy A. Kosterev, Frank K. Tittel, Rüdeger Köhler, Claire Gmachl, Federico Capasso, Deborah L. Sivco, Alfred Y. Cho, Shawn Wehe, and Mark G. Allen, "Thermoelectrically Cooled Quantum-Cascade-Laser-Based Sensor for the Continuous Monitoring of Ambient Atmospheric Carbon Monoxide," Appl. Opt. 41, 1169-1173 (2002)