物理化学学报 >> 1997, Vol. 13 >> Issue (07): 617-620.doi: 10.3866/PKU.WHXB19970708

研究论文 上一篇    下一篇

H2三光子共振增强电离光谱中的反常压力效应

张桂秋,沙国河,许继君,Knott W.Proch D   

  1. 中国科学院大连化学物理研究所 分子反应动力学国家重点实验室,大连 116023|Max-Planck-Institut fur Quantenoptik,P.O.Box 1513,D-85740 Garching,Germany
  • 收稿日期:1996-11-19 修回日期:1997-02-25 发布日期:1997-07-15
  • 通讯作者: 沙国河

Abnormal Pressure Effects of H2 Three-photon Resonant Enhanced Ionization Spectroscopy

Zhang Gui-Qiu,Sha Guo-He,Xu Ji-Jun,Knott W.Proch D   

  1. Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023|Max-Planck-Institut fur Quantenoptik,P.O.Box 1513,D-85740 Garching,Germany
  • Received:1996-11-19 Revised:1997-02-25 Published:1997-07-15
  • Contact: Sha Guo-He

摘要:

在H2B1∑u+-X1∑g+(12,0)和C1Ⅱu-X1∑g+(2,0 )的三光子共振增强多光子电离光谱中观察到反常压力现象,其中有些是首次报导的.线移、线展宽、线分裂和光谱强度的负压效应都可以用三次谐波再吸收的机理解释.用考虑了相位区配条件导出的近似表达式计算的不同压力下线移、线分裂、光谱强度与实验结果一致.用新设计的串联二对电极的气体池得到的光谱直接证明了三次谐波再吸收的机理,圆偏振光实验无信号也支持上述机理.

关键词: 氢气, 反常压力效应, 三光子共振电离光谱, 三次谱波

Abstract:

The three-photon resonant ionization spectroscopy of H2 B1∑u+-X1∑g+ (12,0) and C1Ⅱu-X1∑g+ (2,0) exhibits abnormal pressure effects. Some of them are observed for the first time. Pressure-induced abnormal line shift, line broadening, line splitting and spectral intensity variations can be well explained by a mechanism of reabsorption of the third harmonic generation in the medium. Approximate expressions considering the phase matching requirement yield lineshifts, -splitting and -intensities at different pressures in good agreement with the experimental results. Two similar spectra are detected by two tandem electrode pairs in a gas celll which give experimental evidence for THG reabsorption mechanism. The failure to obtain ion signal from circularly polarized light also supports the above mechanism.

Key words: Molecular hydrogen, Abnormal pressure effects, 3-Photon REMPI, Third harmonic generation