1. 中国科学院安徽光学精密机械研究所大气物理化学研究室，安徽 合肥 230031 2. 中国科学院安徽光学精密机械研究所大气成分与光学重点实验室，安徽 合肥 230031 3. Laboratoire de Physicochimie del’Atmosphère, Université du Littoral Cte d’Opale, 189A, Aν, Maurice Schumann, 59140 Dunkerque, France
Study on the Technology of the 4.4 μm Mid-Infrared Laser Heterodyne Spectrum
TAN Tu1, 2, CAO Zhen-song2, WANG Gui-shi1, 2, WANG Lei1, 2, LIU Kun1, 2, HUANG Yin-bo2, CHEN Wei-dong3, GAO Xiao-ming1, 2*
1. Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics & Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China 2. Key Laboratory of Atmospheric Composition and Optical Radiation, Chinese Academy of Sciences, Hefei 230031, China 3. Laboratoire de Physicochimie del’Atmosphère, Université du Littoral Cte d’Opale, 189A, Aν, Maurice Schumann, 59140 Dunkerque, France
Abstract：In this paper, first time as our knowledge, we describe the development and performance evaluation of a 4.4 μm external cavity quantum cascade laser based laser heterodyne radiometer. Laser heterodyne spectroscopy is a high sensitive laser spectroscopy technique which offers the potential to develop a compact ground or satellite based radiometer for Earth observation and astronomy. An external cavity quantum cascade laser operating at 4.4 μm, with output power up to 180 mW and narrow line width was used as a local oscillation. The external cavity quantum cascade laser offers wide spectral tuning range, it is tunable from 4.38 to 4.52 μm with model hop free and can be used for simultaneous detections of CO2, CO and N2O. A blackbody was used as a signal radiation source. Development and fundamental theory of Laser heterodyne spectroscopy was described. The performance of the developed Laser heterodyne radiometer was evaluated by measuring of CO2 spectral at different pressures. Analyses results showed that a signal-to-noise ratio of 86 was achieved which was less than the theoretical value of 287. The spectral resolution of the developed Laser heterodyne spectroscopy is about 0.007 8 cm-1 which could meet the requirement of high resolution spectroscopy measurement in the case of Doppler linewidth. The experiment showed that middle Infrared laser heterodyne spectroscopy system had high signal-to-noise ratio and spectral resolution, and had broad application prospect in high precision measurement of atmospheric greenhouse gas concentration and vertical profile.
谈 图1，2，曹振松2，王贵师1，2，汪 磊1，2，刘 锟1，2，黄印博2，陈卫东3，高晓明1，2* . 4.4 μm中红外激光外差光谱探测技术研究 [J]. 光谱学与光谱分析, 2015, 35(06): 1516-1519.
TAN Tu1, 2, CAO Zhen-song2, WANG Gui-shi1, 2, WANG Lei1, 2, LIU Kun1, 2, HUANG Yin-bo2, CHEN Wei-dong3, GAO Xiao-ming1, 2*. Study on the Technology of the 4.4 μm Mid-Infrared Laser Heterodyne Spectrum . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2015, 35(06): 1516-1519.
