Characterization of a near-room-temperature, continuous-wave quantum cascade laser for long-term, unattended monitoring of nitric oxide in the atmosphere.
We report on power, spectral linewidth, and mode purity for a cw 5.3 microm quantum cascade laser operated on a thermo-electric cooler. A totally noncryogenic nitric oxide monitor was constructed by integrating this laser with an astigmatic multipass cell and a thermo-electrically cooled infrared detector. The resulting instrument is capable of continuous unattended monitoring of ambient, atmospheric nitric oxide for several weeks with no operator intervention. The detection method was rapid sweep, direct absorption spectroscopy. A detection sensitivity of 0.03 parts in 10(9) is achieved with 30 s averaging time with a path length of 210 m, corresponding to an absorbance path length product of 1.5 x 10(-10) cm(-1).
Nelson
David D
DD
Aerodyne Research, Inc., Billerica, Massachusetts 01821-3976, USA. ddn@aerodyne.com
McManus
J Barry
JB
Herndon
Scott C
SC
Shorter
Joanne H
JH
Zahniser
Mark S
MS
Blaser
Stéphane
S
Hvozdara
Lubos
L
Muller
Antoine
A
Giovannini
Marcella
M
Faist
Jérôme
J