Simultaneous temporally and spectrally resolved Raman coherences with single-shot fs/ns rotational CARS
Simultaneous temporally and spectrally resolved Raman coherences with single-shot fs/ns rotational CARS
复制标题
使用单次 fs/ns 旋转 CARS 同时进行时间和光谱分辨拉曼相干性
作者：
A. Hosseinnia;M. Ruchkina;P. Ding;P. Bengtsson;J. Bood
发展了一种研究分子凝聚动力学的新技术。该概念是基于使用宽带飞秒（fs）激光脉冲的即时激发，而窄带纳秒（ns）激光脉冲探测相干的快速动态。使用条纹相机的光谱分散的相干信号的检测允许在单次拍摄采集中的所有激发的相干性的同时光谱和时间分辨的研究。在这里，我们证明了高容量和多功能性的这种混合fs/ns相干反斯托克斯拉曼散射（汽车）技术通过一些说明性的例子，所有的单次测量，即时间分辨的研究旋转拉曼相干在氮气和空气中，旋转线上的斯塔克效应的动态，和拍现象起源于近躺旋转线。
A novel technique for studies of the dynamics of molecular coherences has been developed. The concept is based on prompt excitation using broadband femtosecond (fs) laser pulses, whereupon a narrowband nanosecond (ns) laser pulse probes the fast dynamics of the coherences. Detection of the spectrally dispersed coherent signal using a streak camera allows simultaneous spectrally and temporally resolved studies of all excited coherences in a single-shot acquisition. Here we demonstrate the high capacity and versatility of this hybrid fs/ns coherent anti-Stokes Raman scattering (CARS) technique through some illustrative examples, all single-shot measurements, namely time-resolved studies of rotational Raman coherences in nitrogen and air, dynamics of Stark effect on rotational lines, and beating phenomena originating from close-lying rotational lines.