Femtosecond Stimulated Raman Spectroscopy

Abstract

Femtosecond stimulated Raman spectroscopy (FSRS) is a new ultrafast spectroscopic technique that provides vibrational structural information with high temporal (50-fs) and spectral (10-cm(1)) resolution. As a result of these unique capabilities, FSRS studies of chemical and biochemical reaction dynamics are expected to grow rapidly, giving previously unattainable insight into the structural dynamics of reactively evolving systems with atomic spatial and femtosecond temporal resolution. This review discusses the experimental and theoretical concepts behind FSRS, with an emphasis on the origins of its unique temporal and spectral capabilities. We illustrate these capabilities with vibrational studies of ultrafast electronic dynamics, as well as the direct structural observation of nonstationary vibrational wave-packet motion in small molecules and in complex biochemical reaction dynamics.

Nonlinear optical signals and spectroscopy with quantum light

“…We now demonstrate the power of this interferometric detection for stimulated Raman signals commonly used to probe molecular vibrations. Applications include probing time-resolved photophysical and photochemical processes (Adamczyk et al, 2009;Kukura et al, 2007;Kuramochi et al, 2012;Schreier et al, 2007), chemically specific biomedical imaging (Cheng et al, 2002), remote sensing (Arora et al, 2012;Pestov et al, 2008). Considerable effort has been devoted to increasing the sensitivity and eliminating off-resonant background, thus improving the signal-to-noise ratio and enabling the detection of small samples and even single molecules.…”

Tracking the primary photoconversion events in rhodopsins by ultrafast optical spectroscopy

“…Thanks to advances in ultrafast optical spectroscopy, with the generation of broadly tuneable fewoptical-cycle light pulses 46 and the introduction of the FSRS technique, 53 it is now possible to track the photoisomerization process of Rh with an unprecedented level of detail. Such progress in experimental techniques has been matched by advances in computational methods, with the introduction of QM/MM methods that allow ab initio simulations with accuracy sufficient to allow comparison with experimental data.…”

“…This dispersive lineshape is typically observed in FSRS when detecting a mode whose frequency changes over a timescale comparable to that of vibrational dephasing. 53,97 Such lineshapes can be simulated rather accurately (red lines in Fig. 12(a)) by assuming that the HOOP frequencies increase by 100 cm −1 from 200 fs to 2 ps, with a 325 fs time constant (see Fig.…”

Ultraviolet-resonance femtosecond stimulated Raman study of the initial events in photoreceptor chromophore

“…The FSRS measurements were carried out by using a combination of pump, probe, and Raman pump pulses [4,5]. Briefly, the fundamental output of a 1-kHz Ti:sapphire amplifier (800 nm) was divided into three.…”