摘要
采用可调谐半导体激光吸收光谱(TDLAS)技术对痕量气体的连续检测,二次谐波背景信号会随着半导体激光器管壳温度变化产生漂移,使得二次谐波波形无法保持稳定,对测量结果产生误差。基于TDLAS原理,解释了二次谐波背景信号的产生,分析了背景信号的来源和背景漂移对测量结果的影响,通过对背景信号的扣除获得标准的二次谐波波形,设计并搭建了一套高精度恒温控制系统,此系统搭载了风冷以及水冷模块进行辅助控温,控制精度达到±0.1℃,选取了1 796和1 653nm波长的DFB半导体激光器,通过控制两只激光器在20~44℃温度条件下来回变动,温度间隔为2℃,对获得的二次谐波背景信号进行了实验研究。研究表明:随着半导体激光器管壳温度上升,背景信号发生红移,反之发生蓝移;实验中温度每变化2℃,1 796和1 653nm的DFB激光器的背景信号分别产生了约3.2和2.67pm波长漂移;通过对半导体激光器进行控温封装,实现对半导体激光器管壳的恒温控制,可以有效地消除室温变化引起的背景信号漂移,维持测量系统的稳定性,提高痕量气体检测的精度和准确度。
As the technique of tunable diode laser absorptionscopy（TDLAS）is employed for trace gas detection,the second-harmonic background signal drifts with the changeof the temperature of semiconductor laser shells.It results in unstability of the second-harmonic signal.Its drifting can cause measurement errors.Based on the principle of TDLAS,the cause of the second harmonic of the background signal is explained.Then the causes of the background signal and its drifting influence on measurement results are analyzed.In addition,the standard second-harmonic signal is obtained after the rejection of background signal.Finally a high-accuracy temperature control systemis designed and it is equipped with air cooling and water cooling modules for auxiliary temperature control.The control precision is between±0.1℃.Moreover,1 796 and 1 653 nm wavelength distrubuted feedback lasers are selected.By controlling the temperature of the two laser shells from 20 to 44 ℃ reversally,the temperature interval is 2 ℃,the experimental results of the second-harmonic background signal are studied.The test results indicate that：As the temperature of semiconductor laser shells rises,the background signal red-shifts;otherwise it blue-shifts.While testing the background signals of the 1 796 and 1 653 nm DFB lasers drift about 3.2 and 2.67 pm respectively at each temperature change of 2 degrees cenigrade.With the constant temperature control of semiconductor laser shells,it can effectively eliminate the influence of the background signal drifting when room temperature changes and enhance the stability of measurement system.The accuracy of trace gas detection is improved.
作者
陈昊
鞠昱
韩立
刘俊标
CHEN Hao;JU Yu;HAN Li;LIU Jun biao(Institute of Electrical Engineering, Chinese Academy of Sciences, 100190 Beijing, China;University of Chinese Academy of Sciences, 100049 Beijing, China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2018年第6期1670-1674,共5页
Spectroscopy and Spectral Analysis
基金
国家重点研发计划项目
重大科学仪器设备开发专项(2017YFF0105100)资助
关键词
气体检测
TDLAS
背景信号漂移
温度特性
Gas cletection
TDLAS
Background signal drift
Temperature characteristic
