光腔衰荡光谱系统设计与信号分析

System design and signal analysis of cavity ring-down absorption spectroscopy

讨论了用连续波半导体激光器做光源的光腔衰荡光谱(CRDS)系统设计及信号分析,介绍了CRDS的工作原理、系统的设计与搭建、谐振腔单模的调节与分析,提出了获取衰荡时间的算法,并在不同波长和光强下,测量了谐振腔(吸收池)的本征衰荡曲线并拟合了相应的衰荡时间.实验结果表明,基于所搭建的CRDS系统,用文中所提出的衰荡时间的采集算法,能够获得稳定性好的衰荡时间,避免光源波动对衰荡时间的影响.

System design and signal analysis of cavity ring-down spectroscopy（CRDS） with the continuous wave diode laser is discussed in this paper, the main content of this paper include the working principle of the CRDS, the system design and building, the adjustment and analysis of the single mode of the resonator, an algorithm of getting the ring down time is also proposed, at thedown curve of the resonator （absorption cell） is measured and the corresponding ring-down time ofoscillation is obtained by fitting the resonator ring down curve at different wavelengthsThe experimental results show that the cavity ring-down time can be obtained based on the proposed CRDSsystem by the proposed algorithm, which can avoid the influence of the light source fluctuation.