Femtosecond spectroscopy of condensed phases with chirped supercontinuum probing
Femtosecond spectroscopy of condensed phases with chirped supercontinuum probing
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DOI：
10.1103/physreva.59.2369
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发表时间：
1999-03-01
影响因子：
2.9
通讯作者：
Ernsting, NP
中科院分区：
文献类型：
--
作者：
Kovalenko, SA;Dobryakov, AL;Ernsting, NP
从理论和实验上发展了具有飞秒时间分辨率的抽运-超连续谱-探测（PSCP）光谱技术。与以前的理论结果nonchirped探测的连接。实验表明，超连续谱可以用单个啁啾脉冲来描述。该技术的一个关键问题-瞬态光谱的精确时间校正-通过监测纯溶剂（液体）或透明基底（固体膜）的非共振电子响应来解决。这允许对超连续谱进行充分的表征，特别是直接测量泵浦-探测互相关的光谱依赖性。对于50 fs泵浦脉冲，理论估计给出了10 fs的时间校正精度，其通常近似于超连续谱脉冲持续时间的1/30。因此，实验上可以实现10-20 fs的时间分辨率。讨论了高频拉曼激发和低频脉冲受激拉曼过程对非共振瞬态信号的贡献。PSCP技术说明了熔融石英和几种常见的溶剂和溶液中的发色团的实验结果。[S1050-2947（99）03303-X]。
Pump-supercontinuum-probe (PSCP) spectroscopy with femtosecond time resolution is developed theoretically and experimentally. The connection to previous theoretical results on nonchirped probing is established. It is experimentally shown that the supercontinuum can be described as a single chirped pulse. A key problem of the technique-the precise time correction of transient spectra-is solved by monitoring the nonresonant electronic response from a pure solvent (liquids) or from a transparent substrate (solid films). This allows for an adequate characterization of the supercontinuum, in particular, for directly measuring the spectral dependence of the pump-probe cross correlation. For 50-fs pump pulses, a theoretical estimate gives an accuracy for the time correction of 10 fs, which is typically approximate to 1/30 of the supercontinuum pulse duration. Hence a time resolution of 10-20 fs can be experimentally realized. Contributions to the nonresonant transient signal from high-frequency Raman excitations and from low-frequency impulsive-stimulated Raman processes are discussed. The PSCP technique is illustrated by results from experiments with fused silica and several common solvents and with a chromophore in solution. [S1050-2947(99)03303-X].