基于DFB激光器的甲烷气体腔衰荡光谱检测技术研究

发布时间：2018-03-03 20:36

本文选题：腔衰荡光谱　切入点：大气　出处：《长春理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：甲烷气体具有易燃易爆的特征,同时还属于引起温室效应的重要因素。所以甲烷的测量一直是环境监测,科学探索的重要方向,对其浓度进行实时在线的检测具有重要意义。本文开展了痕量气体腔衰荡光谱检测技术的理论和实验研究,基于窄线宽DFB激光器,搭建了相关实验装置,并且以甲烷气体浓度实时检测为目的,分析了检测过程中对腔衰荡的影响因素。基于光谱匹配的痕量气体腔衰荡检测系统,能够提供较高的光谱鉴别和灵敏的检测能力,相关技术近年来引起了该领域研究者的广泛关注。随着气体检测技术的不断发展以及人们对空气污染的关注,针对痕量气体的高灵敏度检测技术的研究具有重要意义和实际应用价值。首先,论文研究和分析了光腔衰荡光谱检测系统的腔长、反射镜、激光关断时间等因素对检测结果的影响。并通过腔内能量公式推导了激光器采用不同关断时间对检测数据曲线产生的影响;其次,提出了一种以DFB连续激光器为检测光源的腔衰荡光谱检测方法,通过电流调制波长进行模式匹配及激光关断,简化系统结构。并分析了各部分的工作原理,研究了使用四腔镜环形腔做为衰荡腔的检测方法;最后,以连续激光光源作为基础,建立了光腔衰荡光谱气体检测技术的实验装置,实现了光谱数据的采集,检测并分析了在实验室条件下的甲烷气体浓度。通过扫描波长的方法对甲烷气体在其泛频带的吸收数据进行采集,并针对检测稳定性进行了讨论,最终获得甲烷气体在实验室内部环境中的浓度。
[Abstract]:The characteristics of methane gas with explosive, and it also belongs to the important factors which cause the greenhouse effect. So the methane measurement has been an important direction of environmental monitoring, scientific exploration, has important significance to detect the real-time concentration. This paper carried out theoretical and Experimental Research on the spectral detection of trace gas cavity, narrow line width DFB laser based on built experimental device, and the real-time detection of methane gas concentration for the purpose of analysis of failure factors impact on the swing in the process of detection of trace gases. The cavity cavity ringdown spectrum matching detection system based on spectral identification can provide high sensitive detection capability and related technologies, has aroused widespread concern in the researchers in recent years. With the continuous development of gas detection technology and attention to air pollution, high sensitivity detection technique for trace gas Operation research has important significance and practical value. Firstly, this paper studies and analyzes the CRDs detection system of cavity length, mirror, influence factors of laser off time on the test results. And through the cavity with different laser energy formula shut off time of impact test data curve was derived; secondly, in this paper a DFB laser for the detection of the light source cavity ringdown spectroscopy detection method by current modulation wavelength, laser mode and turn off, simplify the structure of the system and analyzes the working principle of each part of the study using the four mirror ring cavity ring down cavity as the detection method; finally with the continuous laser light source, as a basis, the experimental device of ringdown spectroscopy gas detection technology of optical cavity is established, the spectrum data collection, detection and analysis of methane gas in the laboratory under the condition of strong The absorption data of methane in its wide band were collected by scanning wavelength method, and the stability of detection was discussed. Finally, the concentration of methane in the laboratory environment was obtained.

【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248;O433

【参考文献】