Development of a Quantum Cascade Laser-Based Detector for Ammonia and Nitric Acid

Zahniser, Mark S. ; Nelson, David D. ; McManus, J. Barry ; Shorter, Joanne H. ; Herndon, Scott C. ; Jimenez, Rodrigo

Aerodyne Research, Inc., Billerica, MA

关键词: Light Sources;    Plasma Diagnostics;    Absorption Spectroscopy;    Carbon Monoxide;    Nitrogen Dioxide;   

DOI  :  10.2172/862034
RP-ID  :  DOE/ER/83139-1
RP-ID  :  FG02-01ER83139
RP-ID  :  862034

美国|英语

来源: UNT Digital Library

【 摘 要 】

We have developed a compact, robust, atmospheric trace gas detector based on mid-infrared absorption spectroscopy using pulsed quantum cascade (QC) lasers. The spectrometer is suitable for airborne measurements of ammonia, nitric acid, formaldehyde, formic acid, methane, nitrous oxide, carbon monoxide, nitrogen dioxide and other gases that have line-resolved absorption spectra in the mid-infrared spectral region. The QC laser light source operates near room temperature with thermal electric cooling instead of liquid nitrogen which has been previously required for semiconductor lasers in the mid-infrared spectral region. The QC lasers have sufficient output power so that thermal electric cooled detectors may be used in many applications with lower precision requirements. The instrument developed in this program has been used in several field campaigns from both the Aerodyne Mobile Laboratory and from the NOAA WP3 aircraft. The Phase II program has resulted in more than 10 archival publications describing the technology and its applications. Over 12 instruments based on this design have been sold to research groups in Europe and the United States making the program both a commercial as well as a technological success. Anticipated Benefits The development of a sensitive, cryogen-free, mid-infrared absorption method for atmospheric trace gas detection will have wide benefits for atmospheric and environmental research and broader potential commercial applications in areas such as medical diagnostic and industrial process monitoring of gaseous compounds. Examples include air pollution monitoring, breath analysis, combustion exhaust diagnostics, and plasma diagnostics for semi-conductor fabrication. The substitution of near-room temperature QC lasers for cryogenic lead salt TDLs and the resulting simplifications in instrument design and operation will greatly expand the range of applications.