Effective utilization of quantum-cascade distributed-feedback lasers in absorption spectroscopy

Anatoliy A. Kosterev, Robert F. Curl, Frank K. Tittel, Claire Gmachl, Federico Capasso, Deborah L. Sivco, James N. Baillargeon, Albert L. Hutchinson, Alfred Y. Cho

Research output: Contribution to journalArticlepeer-review

91 Scopus citations


A variable duty cycle quasi-cw frequency scanning technique was applied to reduce thermal effects resulting from the high heat dissipation of type I quantum-cascade lasers. This technique was combined with a 100-m path-length multipass cell and a zero-air background-subtraction technique to enhance detection sensitivity to a parts-in-109(ppb) concentration level for spectroscopic trace-gas detection of CH4, N2O, H2O, and C2H5OH in ambient air at 7.9 μm. A new technique for analysis of dense highresolution absorption spectra was applied to detection of ethanol in ambient air, yielding a 125-ppb detection limit.

Original languageEnglish (US)
Pages (from-to)4425-4430
Number of pages6
JournalApplied Optics
Issue number24
StatePublished - Aug 20 2000
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Engineering (miscellaneous)
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


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