title: [Intra-pulse spectroscopy based on room-temperature pulsed quantum-cascade laser for N2O detection].
abstract: Mid-infrared lasers are very suitable for high-sensitive trace-gases detection in that their wavelengths cover the fundamental absorption lines of most gases. Quantum-cascade lasers have been demonstrated to be ideal light sources with their especially high power, wide range of tuning capability and favorable operating condition on room-temperature. The intra-pulse spectroscopy based on a room-temperature distributed-feedback pulsed QC laser is a simple and effective trace gas detective method to detect trace-gas qualitatively or quantificationally. When a long excitation pulse is applied to a QC laser, the laser frequency tunes almost linearly to lower wave number (lower frequency) as a function of time so all absorption spectral elements are recorded during a single laser pulse. In the present paper, the method was introduced, and identification of N2O spectral fingerprint using this spectroscopy was demonstrated experimentally. The thermal chirp from a 500 ns long excitation pulse was applied to a quantum-cascade laser to get a fast wavelength scanning, thus a wave number tuning of about 1 cm(-1) was produced. The N2O absorption spectrum centered at 1 273.7 cm(-1) was also obtained. The measured absorption spectrum is consistent with HITRAN data precisely.
authors.affiliation: Key Lab of Environmental Optics & Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China. wangmin@aiofm.ac.cn
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Wen-Qing
authors.initials: WQ
authors.lastname: Liu
authors.forename: Rui-Feng
authors.initials: RF
authors.lastname: Kan
authors.forename: Zhen-Yi
authors.initials: ZY
authors.lastname: Chen
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Tang
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Liu