Mid-infrared cavity ring-down spectroscopy (CRDS) using an external cavity, widely tunable pulsed quantum cascade laser operating at 3.8 mu m, was employed for simultaneous detections of ethanol, ether and acetone in this paper. The experiments were performed with a maximum cavity mirror reflectivity of 99.915 % between the wave number 2614 and 2634 cm(-1), leading to an effective optical path length of 588 m. The absorption spectra of ethanol, ether and acetone were measured with high spectral resolution in the range of 2614-2634 cm(-1), and the spectroscopic analysis of the mixture of ethanol, ether and acetone with overlapping absorption spectra was demonstrated. The experimentally achieved detection limits (3 sigma, or three times of standard deviation) for ethanol, ether and acetone were 157, 60 and 280 ppb, respectively. The simultaneously measured concentration results were in good agreement with the results with the standard gravimetric method, indicated that the mid-infrared CRDS has the potential for multi-component trace gas detection as well as for spectroscopic measurements of multi-broadband absorbers.
1.Chinese Acad Sci, Inst Opt & Elect, Chengdu 610209, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Univ Elect & Sci & Technol China, Sch Optoelect Informat, Chengdu 610054, Peoples R China
Zhou, Sheng,Han, Yanling,Li, Bincheng. Simultaneous detection of ethanol, ether and acetone by mid-infrared cavity ring-down spectroscopy at 3.8 mu m[J]. APPLIED PHYSICS B-LASERS AND OPTICS,2016,122(7).