TY - JOUR
T1 - High-Speed Mid-Infrared Frequency Modulation Spectroscopy Based on Quantum Cascade Laser
AU - Peng, Chen
AU - Chen, Gang
AU - Tang, Jianping
AU - Wang, Lijun
AU - Wen, Zhongquan
AU - Zhou, Haijun
AU - Martini, Rainer
N1 - Publisher Copyright:
© 2016 IEEE.
PY - 2016/8/15
Y1 - 2016/8/15
N2 - We demonstrated a high-speed mid-infrared frequency modulation spectroscopy scheme based on a distributed-feedback quantum Cascade laser for the application in trace gas sensing by means of all-optical frequency modulation. With this method, the modulation frequency spectrum of a gas sample can be obtained within the mid-infrared pulse duration of ∼ 200 ns. A frequency modulation of the middle infrared lasing optical frequency was achieved in quantum Cascade laser with a modulation frequency of 200 MHz by illuminating with a 1550-nm near-infrared laser. For CO gas, with 2-mW near-infrared illumination, the noise-equivalent sensitivity of the frequency modulation spectroscopy was estimated to be 0.12 ppmv for an absorption length of 6.1 m, indicating an improvement by a factor of 7 compared with Voigt-fitted direct absorption spectroscopy (0.84 ppmv). The frequency modulation signal was found to be proportional to the incident near-infrared power, and therefore, the noise-equivalent sensitivity is expected to be further improved by increasing the near-infrared illumination power. This high-speed frequency modulation spectroscopy based on the distributed-feedback quantum Cascade laser has promising applications in high-speed and high-sensitivity gas sensing.
AB - We demonstrated a high-speed mid-infrared frequency modulation spectroscopy scheme based on a distributed-feedback quantum Cascade laser for the application in trace gas sensing by means of all-optical frequency modulation. With this method, the modulation frequency spectrum of a gas sample can be obtained within the mid-infrared pulse duration of ∼ 200 ns. A frequency modulation of the middle infrared lasing optical frequency was achieved in quantum Cascade laser with a modulation frequency of 200 MHz by illuminating with a 1550-nm near-infrared laser. For CO gas, with 2-mW near-infrared illumination, the noise-equivalent sensitivity of the frequency modulation spectroscopy was estimated to be 0.12 ppmv for an absorption length of 6.1 m, indicating an improvement by a factor of 7 compared with Voigt-fitted direct absorption spectroscopy (0.84 ppmv). The frequency modulation signal was found to be proportional to the incident near-infrared power, and therefore, the noise-equivalent sensitivity is expected to be further improved by increasing the near-infrared illumination power. This high-speed frequency modulation spectroscopy based on the distributed-feedback quantum Cascade laser has promising applications in high-speed and high-sensitivity gas sensing.
KW - Frequency modulation spectroscopy
KW - gas sensing
KW - middle-infrared spectroscopy
KW - quantum cascade laser
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U2 - 10.1109/LPT.2016.2554359
DO - 10.1109/LPT.2016.2554359
M3 - Article
AN - SCOPUS:84976560827
SN - 1041-1135
VL - 28
SP - 1727
EP - 1730
JO - IEEE Photonics Technology Letters
JF - IEEE Photonics Technology Letters
IS - 16
M1 - 7452592
ER -