Extracting Phase and Amplitude Modifications of Laser-Coupled Fano Resonances
Extracting Phase and Amplitude Modifications of Laser-Coupled Fano Resonances
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DOI：
10.1103/physrevlett.112.103001
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发表时间：
2014-03-10
影响因子：
8.6
通讯作者：
Pfeifer, Thomas
中科院分区：
文献类型：
--
作者：
Kaldun, Andreas;Ott, Christian;Pfeifer, Thomas
在吸收光谱中观察到的法诺线形状编码关于光学偶极响应的振幅和相位的信息。法诺线形状的变化，例如，通过与短脉冲激光场的相互作用，使我们能够提取耦合激发量子态的振幅和相位的动态修改。我们介绍并应用这一物理机制的近共振耦合双激发态氦。这种一般的方法提供了一个物理上的理解，激光诱导的吸收线最大值的光谱偏移的子激光周期的时间尺度，因为它们是无处不在的观察阿秒瞬态吸收测量。
Fano line shapes observed in absorption spectra encode information on the amplitude and phase of the optical dipole response. A change in the Fano line shape, e.g., by interaction with short-pulsed laser fields, allows us to extract dynamical modifications of the amplitude and phase of the coupled excited quantum states. We introduce and apply this physical mechanism to near-resonantly coupled doubly excited states in helium. This general approach provides a physical understanding of the laser-induced spectral shift of absorption-line maxima on a sub-laser-cycle time scale as they are ubiquitously observed in attosecond transient-absorption measurements.