可调谐二极管激光吸收光谱技术在探测灵敏度上的探讨

可调谐二极管激光吸收光谱(TDLAS)技术是利用二极管激光器波长调谐特性,获得被测气体在特征吸收光谱范围内的吸收光谱,从而对污染气体进行定性或定量的分析的一种技术方法.在对痕量气体的监测时一般会采取一定的措施去克服直接吸收型气体传感器的缺陷,提高检测精度.文中概述了TDLAS技术的研究现状,针对近年来国内外出现的基于可调谐二极管激光吸收光谱技术在减小系统干扰,提高探测灵敏度的技术措施,从系统结构处理,调制解调技术,检测装置的处理,检测信号的处理等多个方面作了深入的研讨.

Some discussion about detection sensitivity of tunable diode laser absorption spectroscopic technology

Tunable diode laser absorption spectroscopic (TDLAS) technology applies the wavelength tunable characteristics of diode lasers to gain the absorp- tion spectroscopy of the selected absorption line of the target gas for the qualitative and/or quantitative analysis of the pollution gases in air.Some certain measures were generally taken to overcome the flaw of the direct absorption gas sensor in order to improve the precision of measuring when to monitor trace gas.The present situation of the TDLAS technology was outlined in this paper.The thorough discussion were done from system structure processing,the modulation and demodula- tion technology,the treatment of detection devices,the processing of the testing signal and so on many aspects in view of the emergence of domestic and foreign- based on the TDLAS technology reduced the system disturbance and raised the detection sensitivity in recent years.