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NASA NTRS · 20040088812

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

Kosterev, A. A.·Curl, R. F.·Tittel, F. K.·Gmachl, C.·Capasso, F.·Sivco, D. L.·Baillargeon, J. N.·Hutchinson, A. L.·Cho, A. Y.
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Abstract

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-10(9) (ppb) concentration level for spectroscopic trace-gas detection of CH4, N2O, H2O, and C2H5OH in ambient air at 7.9 micrometers. A new technique for analysis of dense high resolution absorption spectra was applied to detection of ethanol in ambient air, yielding a 125-ppb detection limit.

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NASA Discipline Environmental HealthNon-NASA CenterSpectrophotometry, Atomic/instrumentationLasersGases/analysisAir Pollution, Indoor/analysisEnvironmental Monitoring/instrumentationLinear ModelsEvaluation StudiesMethane/analysisEquipment DesignNitrous Oxide/analysisWater/analysisEthanol/analysisSupport, Non-U.S. Gov'tTemperatureSupport, U.S. Gov't, Non-P.H.S

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Kosterev, A. A., Curl, R. F., Tittel, F. K., Gmachl, C., Capasso, F., Sivco, D. L., Baillargeon, J. N., Hutchinson, A. L., Cho, A. Y.. 2000-08-20. Effective utilization of quantum-cascade distributed-feedback lasers in absorption spectroscopy. https://ntrs.nasa.gov/citations/20040088812

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