利用2.8微米法拉第旋转光谱法对羟基自由基进行灵敏且选择性的检测。

Sensitive and selective detection of OH radicals using Faraday rotation spectroscopy at 2.8 µm.

作者信息

Zhao Weixiong, Wysocki Gerard, Chen Weidong, Fertein Eric, Le Coq David, Petitprez Denis, Zhang Weijun

机构信息

Laboratoire de Physicochimie de l’Atmosphère, Université du Littoral Côte d’Opale, 189A Av Maurice Schumann, 59140 Dunkerque, France.

出版信息

Opt Express. 2011 Jan 31;19(3):2493-501. doi: 10.1364/OE.19.002493.

DOI:10.1364/OE.19.002493

PMID:21369069

Abstract

We report on the development of a Faraday rotation spectroscopy (FRS) instrument using a DFB diode laser operating at 2.8 µm for the hydroxyl (OH) free radical detection. The highest absorption line intensity and the largest gJ value make the Q (1.5) double lines of the 2Π3/2 state (υ = 1 ← 0) at 2.8 µm clearly the best choice for sensitive detection in the infrared region by FRS. The prototype instrument shows shot-noise dominated performance and, with an active optical pathlength of only 25 cm and a lock-in time constant of 100 ms, achieves a 1σ detection limit of 8.2 × 10(8) OH radicals/cm3.

摘要

我们报告了一种用于检测羟基（OH）自由基的法拉第旋转光谱（FRS）仪器的开发情况。该仪器使用工作在2.8 µm的分布反馈（DFB）二极管激光器。2.8 µm处2Π3/2态（υ = 1 ← 0）的Q（1.5）双线具有最高的吸收线强度和最大的gJ值，显然是FRS在红外区域进行灵敏检测的最佳选择。该原型仪器表现出散粒噪声主导的性能，有效光程仅25 cm，锁定时间常数为100 ms，实现了8.2×10(8)个OH自由基/cm3的1σ检测限。