大气压附近不同温度对碘气体简并四波混频光谱的影响

Effects of different atmospheric pressures and temperatures on degenerate four-wave mixing spectroscopy in iodine vapor

非线性激光光谱技术在气相介质的痕迹量检测方面有广泛应用。实验采用了具有自稳分光系统的前向简并四波混频（DFWM）布局，在大气压附近不同压强和不同温度条件下研究了碘气体的DFWM光谱。在饱和泵浦和探测光强的情况下，发现温度与压强的变化对碘在波长555~556 nm及558~559 nmDFWM光谱结构影响较大，其中波长为555.1 nm 的跃迁对温度相当敏感。同时仍有少数碘的DFWM光谱线较强是因为跃迁（558.81 nm）对温度不敏感，可以利用该谱线来探测不同温度下气相介质的浓度变化。所以不同温度与压强对碘气体DFWM光谱影响的研究在气相介质痕迹量的检测以及燃烧诊断等方面有重要的应用价值。

Nonlinear laser spectroscopy has been widely applied for species trace in the gas-media. Forward DFWM with a self-stability beam-spiltting system was demonstrated in iodine vapor at different temperatures and pressures. It is found that the effects of the variable temperature and pressure on DFWM spectra structure （555-556 nm and 558-559 nm） are vivid under the saturated pumping and probing situation, and first of all, a wavelength （555.1 nm） sensitive to temperature in the atmospheric pressure is found. Also the wavelengths（558.81 nm） insensitive to temperatures, which the wavelength can be used to measure the gas-phase media concentration at varied temperatures. Effects of different temperatures and atmospheric pressures on the DFWM spectroscopy in iodine vapor at atmospheric pressure are of importance to trace atom, molecular and radical in combustion diagnosis.