Experiment and analysis of two-photon absorption spectroscopy using a white-light continuum probe
Experiment and analysis of two-photon absorption spectroscopy using a white-light continuum probe
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DOI：
10.1109/jqe.2002.802448
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发表时间：
2002-11
影响因子：
2.5
通讯作者：
R. Negres;J. Hales;A. Kobyakov;D. Hagan;E. W. Stryland
中科院分区：
文献类型：
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作者：
R. Negres;J. Hales;A. Kobyakov;D. Hagan;E. W. Stryland
我们提出了一种沿着的实验技术和数据分析的方法来给出非简并双光子吸收（2PA）谱。我们使用飞秒泵浦脉冲和白光连续谱（WLC）探针快速产生各种材料的2PA光谱。为了分析用这种方法采集的数据，必须知道WLC的光谱和时间特征沿着样品的线性色散。这允许确定泵浦和探测脉冲的时间走离作为由群速度失配引起的频率的函数。然后可以执行数据校正以获得非线性损失。我们推导出一个解析公式的归一化非线性透射率是有效的相当一般的实验参数下。我们验证了这对ZnS和使用它来确定一些有机化合物在溶液中的2PA光谱。我们还比较了一些有机物的数据与双光子荧光数据，发现很好的协议。
We present an experimental technique along with the method of data analysis to give nondegenerate two-photon absorption (2PA) spectra. We use a femtosecond pump pulse and a white-light continuum (WLC) probe to rapidly generate the 2PA spectra of a variety of materials. In order to analyze data taken with this method, the spectral and temporal characteristics of the WLC must be known, along with the linear dispersion of the sample. This allows determination of the temporal walk-off of the pump and probe pulses as a function of frequency caused by group-velocity mismatch. Data correction can then be performed to obtain the nonlinear losses. We derive an analytical formula for the normalized nonlinear transmittance that is valid under quite general experimental parameters. We verify this on ZnS and use it for the determination of 2PA spectra of some organic compounds in solution. We also compare some of the data on organics with two-photon fluorescence data and find good agreement.