Multi-Pass Absorption Spectroscopy for CO Detection Using a Quantum Cascaded Laser
LI Chun-guang1, DANG Jing-min1, CHEN Chen2*, WANG Yi-ding1*
1. State Key Laboratory on Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China 2. National Engineering Research Center of Geophysics Exploration Instruments, College of Instrumentation & Electrical Engineering, Jilin University, Changchun 130061, China
Abstract:According to the fundamental absorption properties of Carbon Monoxide(CO) near 4.7 μm, a novel CO sensor was designed using a Quantum Cascaded Laser (QCL) whose central wavelength is 4.75 μm and Multi-pass Gas Cell (MGC). This sensor uses a QCL with the thermoelectrically cooled function and can work under pulse mode and room temperature, the exiting optical wavelength was located in a strong absorption line (2 103 cm-1)which is in the base band of CO through adjusting the injection current and temperature. Meanwhile, a novel MGC (40 cm long and 800 mL sampling volume) with 16 meters effective optical path length and mercury cadmium telluride mid-infrared detectors was used, thus effectively improved the sensitivity of this system. Additionally, a reference gas cell and a spatial filtering optical structure were occupied, resulting in effective improvement of the beam quality and reduction of the noise caused by the instability of QCL, the sensitivity of this system was improved furtherly. It indicated that the system works stably by means of multiple measurements to the carbon monoxide gas with different concentration, a detection limit of 5 μmol·mol-1 can be obtained when the signal-to-noise ratio equals 1.
Key words:Carbon Monoxide;Quantum cascaded laser;Multi-pass gas cell;Spatial filtering
李春光1,党敬民1,陈 晨2*,王一丁1*. 使用量子级联激光器和多通吸收光谱技术用于CO探测[J]. 光谱学与光谱分析, 2016, 36(05): 1308-1312.
LI Chun-guang1, DANG Jing-min1, CHEN Chen2*, WANG Yi-ding1*. Multi-Pass Absorption Spectroscopy for CO Detection Using a Quantum Cascaded Laser. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2016, 36(05): 1308-1312.
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