Applied Physics B

, Volume 72, Issue 7, pp 865–872

Oxygen measurements at high pressures with vertical cavity surface-emitting lasers

  • J. Wang
  • S.T. Sanders
  • J.B. Jeffries
  • R.K. Hanson

DOI: 10.1007/s003400100539

Cite this article as:
Wang, J., Sanders, S., Jeffries, J. et al. Appl Phys B (2001) 72: 865. doi:10.1007/s003400100539

Abstract.

Measurements of oxygen concentration at high pressures (to 10.9 bar) were made using diode-laser absorption of oxygen A-band transitions near 760 nm. The wide current-tuning frequency range (>30 cm-1) of vertical cavity surface-emitting lasers (VCSELs) was exploited to enable the first scanned-wavelength demonstration of diode-laser absorption at high pressures; this strategy is more robust than fixed-wavelength strategies, particularly in hostile environments. The wide tuning range and rapid frequency response of the current tuning were further exploited to demonstrate wavelength-modulation absorption spectroscopy in a high-pressure environment. The minimum detectable absorbance demonstrated, ∼1×10-4, corresponds to ∼800 ppm-m oxygen detectivity at room temperature and is limited by etalon noise. The rapid- and wide-frequency tunability of VCSELs should significantly expand the application domain of absorption-based sensors limited in the past by the small current-tuning frequency range (typically <2 cm-1) of conventional edge-emitting diode lasers.

PACS: 07.07.Df; 42.62.Fi; 42.55.Px

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • J. Wang
    • 1
  • S.T. Sanders
    • 1
  • J.B. Jeffries
    • 1
  • R.K. Hanson
    • 1
  1. 1.High Temperature Gasdynamics Laboratory, Department of Mechanical Engineering, Stanford University, Stanford, California 94305-3032, USAUS