Lewicki Rafal, Doty James H, Curl Robert F, Tittel Frank K, Wysocki Gerard
Rice Quantum Institute, Rice University, 6100 Main Street, Houston, TX 77005, USA.
Proc Natl Acad Sci U S A. 2009 Aug 4;106(31):12587-92. doi: 10.1073/pnas.0906291106. Epub 2009 Jul 22.
A transportable prototype Faraday rotation spectroscopic system based on a tunable external cavity quantum cascade laser has been developed for ultrasensitive detection of nitric oxide (NO). A broadly tunable laser source allows targeting the optimum Q(3/2)(3/2) molecular transition at 1875.81 cm(-1) of the NO fundamental band. For an active optical path of 44 cm and 1-s lock-in time constant minimum NO detection limits (1sigma) of 4.3 parts per billion by volume (ppbv) and 0.38 ppbv are obtained by using a thermoelectrically cooled mercury-cadmium-telluride photodetector and liquid nitrogen-cooled indium-antimonide photodetector, respectively. Laboratory performance evaluation and results of continuous, unattended monitoring of atmospheric NO concentration levels are reported.
基于可调谐外腔量子级联激光器开发了一种可运输的法拉第旋转光谱系统，用于超灵敏检测一氧化氮（NO）。宽可调谐激光源能够瞄准NO基频带中1875.81 cm⁻¹处的最佳Q(3/2)(3/2)分子跃迁。对于44 cm的有效光路和1 s的锁定时间常数，分别使用热电冷却的汞镉碲光电探测器和液氮冷却的锑化铟光电探测器，获得的最低NO检测限（1σ）为4.3体积十亿分比（ppbv）和0.38 ppbv。报告了实验室性能评估以及大气NO浓度水平的连续无人值守监测结果。
