Applied Physics B

, Volume 75, Issue 2–3, pp 261–265 | Cite as

Sensitive absorption measurements in the near-infrared region using off-axis integrated-cavity-output spectroscopy

  • D.S. Baer
  • J.B. Paul
  • M. Gupta
  • A. O’Keefe

Abstract.

A novel instrument that employs a high-finesse optical cavity as an absorption cell has been developed for sensitive measurements of gas mixing ratios using near-infrared diode lasers and absorption-spectroscopy techniques. The instrument employs an off-axis trajectory of the laser beam through the cell to yield an effective optical path length of several kilometers without significant unwanted effects due to cavity resonances. As a result, a minimum detectable absorption of approximately 1.4×10-5 over an effective optical path of 4.2 km was obtained in a 1.1-Hz detection bandwidth to yield a detection sensitivity of approximately 3.1×10-11 cm-1 Hz-1/2. The instrument has been used for sensitive measurements of CO, CH4, C2H2 and NH3.

PACS: 42.79.P; 78.40.M; 33.55.A 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  • D.S. Baer
    • 1
  • J.B. Paul
    • 1
  • M. Gupta
    • 1
  • A. O’Keefe
    • 1
  1. 1.Los Gatos Research, 67 East Evelyn Avenue, Suite 3, Mountain View, CA 94041–1518, USAUS

Personalised recommendations