基于脉冲石英增强光声光谱的中红外超高灵敏CO探测  

Mid-IR Ultra-Sensitive CO Detection Based on Pulsed Quartz Enhanced Photoacoustic Spectroscopy

作　　者：董磊[1] 马维光[1] 张雷[1] 尹王保[1] 贾锁堂[1] 

机构地区：[1]山西大学激光光谱研究所,量子光学与光量子器件国家重点实验室,山西太原030006

出　　处：《光学学报》2014年第1期287-291,共5页Acta Optica Sinica

基　　金：国家973计划(2012CB921603);国家自然科学基金(61275213,61108030,61127017,61178009,60908019,61205216);山西省青年科学基金(2013021004-1,2012021022-1);山西省回国留学人员科研资助项目(2013-011);山西省留学回国人员科技活动资金(2013-01)

摘　　要：发展了一种超高灵敏的CO痕量气体测量装置，该装置采用4．65nm脉冲式中红外外腔量子级联激光器作为激发光源，结合石英增强光声光谱技术，对2135～2225cm-1之间的CO基频振动光谱带R支进行连续光谱扫描。水被加入到被测气体中，以加快较慢的CO分子振动-平动弛豫率。在锁相放大器时间常数为3ms，激光器占空比和扫描速率为50％和18cm-1／s时，获得的最小探测极限为4．6×10^-8（体积分数），与之对应的归一化噪声等特吸忻桑麴为1．07×10—8cm-1W／√Hz．An ultra-sensitive gas sensor for trace carbon monoxide （CO） detection is developed. The fundamental ro- vibrational absorption bands of CO from 2135 cm-1 to 2225 cm 1 is continuously measured using a 4.65 μm pulsed external-cavity quantum cascade laser and quartz enhanced photoacoustic spectroscopy. The water vapor, acting as a catalyst for vibrational energy transfer, is added to the targeted analyte mixture to improve signal amplitude. A detection limit of 4.6 × 10-8 is obtained for 3-ms lock-in amplifier time constant at atmospheric pressure with a laser scan rate of 18 cm-1/s and a 50 % duty cycle, which corresponds to a normalized equivalent absorption coefficient of 1.07×10-8 cm 1W/√Hz.

关 键 词：光谱学 超高灵敏CO测量 石英增强光声光谱 中红外量子级联激光器 

分 类 号：O433.1[机械工程—光学工程] P659.21[理学—光学]