Trace-gas detection in ambient air with a thermoelectrically cooled, pulsed quantum-cascade distributed feedback laser |
| |
Authors: | Kosterev A A Tittel F K Gmachl C Capasso F Sivco D L Baillargeon J N Hutchinson A L Cho A Y |
| |
Affiliation: | Rice Quantum Institute, Rice University, Houston, Texas 77251-1892, USA. akoster@rice.edu |
| |
Abstract: | A pulsed quantum-cascade distributed feedback laser operating at near room temperature was used for sensitive high-resolution IR absorption spectroscopy of ambient air at a wavelength of ~8 mum. Near-transform-limited laser pulses were obtained owing to short (~5-ns) current pulse excitation and optimized electrical coupling. Fast and slow computer-controlled frequency scanning techniques were implemented and characterized. Fast computer-controlled laser wavelength switching was used to acquire second-derivative absorption spectra. The minimum detectable absorption was found to be 3 x 10(-4) with 10(5) laser pulses (20-kHz repetition rate), and 1.7 x 10(-4) for 5 x 10(5) pulses, based on the standard deviation of the linear regression analysis. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|