基于室温脉冲量子级联激光器的NO气体检测中的光谱处理方法研究

Spectroscopy processing for the NO measurement based on the room-temperature pulsed quantum cascade laser

报导了采用基于室温脉冲量子级联激光器的脉内光谱检测技术,利用中心波长为1904cm-1的量子级联激光器,在实验室对NO气体样品进行检测的研究结果.针对单线直接吸收光谱反演算法进行了研究,介绍了基线拟合的最小二乘算法以获取其吸光度,根据HITRAN数据库中相应吸收谱线的吸收线强,采用扫描积分实现了气体浓度的反演,避免了标气标定造成的误差及污染;通过拟合残差分析得到了系统的检测限,达到3.4×10-6m.

The intra-pulse spectroscopy based on room-temperature pulsed quantum cascade（QC） lasers was introduced.With a room-temperature pulsed QC laser centered at 1904 cm-1,the sample NO gas has been detected.The least-squared algorithm of baseline fitting and concentration retrieving method were introduced for the single line spectroscopy detection,and the gas concentration can be calculated with scan integration and the corresponding values from HITRAN04 database by direct-absorption technique,without calibration.The detection limit was obtained by analyzing the residual of the absorption spectroscopy as 3.4×10-6m.