基于瞬态光克尔效应的超快光学快门技术

Ultrafast optical gating techniques based on transient optical Kerr effect

系统介绍了几种基于瞬态光克尔效应的超快光学快门技术,包括传统的光克尔双折射快门技术,瞬态光栅快门技术,以及利用瞬态克尔透镜效应的光学快门技术。这些技术都是在泵浦-探测的实验配置基础上,利用门控光对克尔介质折射率的瞬态调制导致的信号光的相位(偏振态)、传播方向或光束发散角等光学特性的改变实现对信号光的超快时间分辨测量。对比讨论了这些超快快门技术的工作原理和实验配置,结果表明瞬态光束偏折快门技术相比其他快门技术具有无偏振配置要求、无相位匹配条件、超宽带光谱响应范围的特点,在光与物质相互作用的超快动力学研究中具有更为广阔的应用前景。

Several ultrafast optical gating techniques based on transient optical Kerr effect are introduced, including tradi- tional optical Kerr birefringence gating technique, transient grating optical gating technique, and transient optical Kerr lens gating techniques. All the techniques are based on pump-probe experimental setup. Utilizing the change of the phase （polarization）, propagation direction or the beam divergence of the signal beam induced by the transient modulation of Kerr materials~ refractive index, the ultrafast time-resolved spectra of the signal beam could be obtained by scanning the pump-probe delay. By comparing their working principles and experimental setups, it is demonstrated that the transient beam deflection optical gating technique has extended measurable probe bandwidth with no requirements of pump-probe polarization configuration and phase matching condi- tions, thus it can be widely used in ultrafast broadband time-resolved spectroscopy.