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Applied Optics

Applied Optics


  • Editor: Joseph N. Mait
  • Vol. 48, Iss. 27 — Sep. 20, 2009
  • pp: 5061–5066

Enhanced sensitivity for the detection of trace gases using multiple line integrated absorption spectroscopy

Andreas Karpf and Gottipaty N. Rao  »View Author Affiliations

Applied Optics, Vol. 48, Issue 27, pp. 5061-5066 (2009)

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We describe a technique that enhances the sensitivity of a spectrometer for trace gas detection employing an external cavity continuously tunable CW quantum cascade laser and integrating the absorption spectra across multiple lines of the species. We demonstrate the power of this method by continuously recording the absorption spectra of N O 2 across the R branch from 1628.8 to 1634.5 cm 1 . By integrating the resulting spectra, the detection sensitivity of N O 2 is improved by a factor of 15 compared to the sensitivity achieved using single line laser absorption spectroscopy with the same apparatus. This procedure offers much shorter data acquisition times for the real-time monitoring of trace gas species compared to adding repeated scans of the spectra to improve the signal-to-noise ratio.

© 2009 Optical Society of America

OCIS Codes
(000.2170) General : Equipment and techniques
(010.1120) Atmospheric and oceanic optics : Air pollution monitoring
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
(280.3420) Remote sensing and sensors : Laser sensors
(300.1030) Spectroscopy : Absorption
(300.6340) Spectroscopy : Spectroscopy, infrared

ToC Category:

Original Manuscript: May 6, 2009
Revised Manuscript: August 3, 2009
Manuscript Accepted: August 21, 2009
Published: September 10, 2009

Andreas Karpf and Gottipaty N. Rao, "Enhanced sensitivity for the detection of trace gases using multiple line integrated absorption spectroscopy," Appl. Opt. 48, 5061-5066 (2009)

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