Short laser pulses are widely used for controlling molecular rotational degrees of freedom and inducing molecular alignment, orientation, unidirectional rotation, and other types of coherent rotational motion. To follow the ultrafast rotational dynamics in real time, several techniques for producing molecular movies have been proposed based on the Coulomb explosion of rotating molecules, or recovering molecular orientation from the angular distribution of high harmonics. The present work offers and demonstrates a novel nondestructive optical method for direct visualization and recording of movies of coherent rotational dynamics in a molecular gas. The technique is based on imaging the time‐dependent polarization dynamics of a probe light propagating through a gas of coherently rotating molecules. The probe pulse continues through a radial polarizer, and is then recorded by a camera. The technique is illustrated by implementing it with two examples of time‐resolved rotational dynamics: alignment–antialignment cycles in a molecular gas excited by a single linearly polarized laser pulse, and unidirectional molecular rotation induced by a pulse with twisted polarization. This method may open new avenues in studies on fast chemical transformation phenomena and ultrafast molecular dynamics caused by strong laser fields of various complexities.

中文翻译：

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相干分子转子的光学成像

短激光脉冲广泛用于控制分子旋转的自由度，并诱导分子排列，定向，单向旋转和其他类型的相干旋转运动。为了实时跟踪超快速旋转动力学，已经提出了几种基于旋转分子的库仑爆炸或从高次谐波的角度分布恢复分子取向的分子电影的技术。本工作提供并演示了一种新颖的非破坏性光学方法，用于直接可视化和记录分子气体中相干旋转动力学的电影。该技术基于对通过相干旋转分子气体传播的探测光的时间相关偏振动力学进行成像。探测脉冲继续通过径向偏振器，然后由照相机记录下来。通过用两个时间分辨的旋转动力学示例来实现该技术来说明该技术：在单个线性偏振激光脉冲激发的分子气体中的排列-反排列循环，以及在扭曲偏振脉冲的作用下引起的单向分子旋转。该方法可为研究各种复杂性强激光场引起的快速化学转化现象和超快速分子动力学开辟新的途径。和具有扭曲极化脉冲的单向分子旋转。该方法可以为研究各种复杂性的强激光场引起的快速化学转化现象和超快速分子动力学开辟新的途径。和具有扭曲极化的脉冲引起的单向分子旋转。该方法可为研究各种复杂性强激光场引起的快速化学转化现象和超快速分子动力学开辟新的途径。