近红外波段CO_2分子弛豫动力学效应对光声信号的影响  

The Influence of CO_2 Molecular Relaxation Dynamics on Photoacoustic Signal in Near Infrared (NIR) Range

作　　者：李劲松[1] 刘锟[1] 张为俊[1] 陈卫东 高晓明[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所环境光谱学研究室,安徽合肥230031 [2]法国滨海大学大气物理化学实验室,法国敦克尔克59140

出　　处：《光谱学与光谱分析》2008年第9期1953-1957,共5页Spectroscopy and Spectral Analysis

基　　金：国家高技术研究发展计划项目(2006AA06Z237)资助

摘　　要：介绍了一种基于低功率的分布反馈式(DFB)半导体激光器和自行设计的一阶纵向共振光声池构成的共振光声光谱测量系统。该系统具有结构简单、操作方便、价格低廉等优点。通过对光声池的性能进行的研究,实验研究和理论分析具有很好的一致性;系统地研究了近红外1.573μm附近分子弛豫效应对光声探测CO2信号的影响,并给出了相应的理论分析,表明利用分子弛豫效应可有效地提高系统探测灵敏度。Photoacoustic spectroscopy （PAS） based on tunable diode laser （TDLPAS） is a widely recognised method for its excellent performance in trace gas monitoring and spectral analysis. This spectral technique provides many advantages such as high selectivity and sensitivity, on-line, real time and contactless measurements in a compact experimental arrangement. In the present paper, a resonant PA spectrometer based on a low-power near infrared distributed feedback （DFB） diode laser and a home-made resonant PA cell operating on its first longitudinal mode is developed, and the PA system has the advantage of simple experimental setup, easy operation, and low-cost, room temperature operating, etc. By investigating the performances of the PA cell at first, a good agreement was achieved between experimental and theoretical results; we have systematically investigated the influence of molecular relaxation effect on the PA detection of CO2 molecule near 1.573 μm, and presented the relevant analysis in theory. The research result shows that the detection sensitivity of the system based on PAS technique can be effectively improved by using the molecular relaxation effect.

关 键 词：近红外可调谐二极管激光 共振光声光谱 CO2探测 分子弛豫效应 

分 类 号：O433.5[机械工程—光学工程]