基于分布反馈激光器双波长调制的微量气体测量方法  

Trace Gas Measurement Method Based on Dual Wavelength Modulation of Distributed Feedback Laser

作　　者：李志军[1,2] 陈伟根[1] 季焱 曹玲燕[2] 吴淼[4] 张建学[2] 禚莉[2] 喻勇高 

机构地区：[1]重庆大学电气工程学院,四川重庆400044 [2]国电南京自动化股份有限公司,江苏南京211153 [3]武汉理工大学物理系,湖北武汉430070 [4]无锡出入境检验检疫局,江苏无锡214001 [5]武汉华工先舰电气股份有限公司,湖北武汉430205

出　　处：《激光与光电子学进展》2017年第11期220-225,共6页Laser & Optoelectronics Progress

摘　　要：在光声光谱测量中,常用光学斩波器对光源输出信号进行频率调制,但光学斩波器的使用会不可避免地增加系统噪声及系统成本。基于分布反馈激光器的可调谐特性,提出激光器双波长调制方法。利用光声光谱实验平台,结合光学斩波器调制激光系统进行检测甲烷气体灵敏度的实验。结果表明,光学斩波器对甲烷气体的检测灵敏度为52.3×10-6,而双波长调制激光系统的检测灵敏度可达40.2×10-6,该调制方法避免了光学斩波器的使用,减小了系统噪声,提高了系统灵敏度。In photoacoustic spectrum measurement, optical chopper is commonly used to modulate frequency of light source output signal, however, the use of optical chopper inevitably leads to the increase of noise and cost of the system. On the basis of the tunable characteristics of distributed feedback laser, a dual wavelength modulation metod of the laser is proposed. Using photoacoustic spectroscopy experimental platform with optical chopper modulation laser system, we carry out the detection sensitivity experiment of methane. The results show that the detection sensitivity of optical chopper to methane is 52.3 ×10^-6 , and that of the dual wavelength modulation laser system to methane is 40.2×10^-6 . The dual wavelength modulation method avoids the use of optical chopper, decreases the system noise, and improves the system sensitivity.

关 键 词：激光器 光声光谱 分布反馈激光器 气体检测 双波长调制 

分 类 号：TN249[电子电信—物理电子学]