Probe effects on time decays of coherent anti-Stokes Raman signals of isolated transitions

TL;DR

This paper demonstrates that probe pulse-shape effects cause deviations in time-resolved coherent anti-Stokes Raman signals from simple exponential decay, impacting linewidth measurements and improving agreement between theory and experiment.

Contribution

It reveals the influence of probe pulse-shape effects on Raman signal decay and provides corrections that enhance the accuracy of linewidth measurements.

Findings

Probe pulse-shape effects cause deviations from exponential decay.

Corrected linewidth measurements show improved agreement with theory.

Spectral filtering explains the observed deviations.

Abstract

We show that time-resolved coherent anti-Stokes Raman signals of isolated transitions deviate from the exponential decay whose time constant is nowadays used for measuring Raman linewidths. The deviation is caused by probe pulse-shape effects that can be understood in terms of the spectral filtering created by the necessary action of laser probing. Consequent corrections to recent linewidth measurements on heteronuclear molecules support the unprecedented agreement between theoretical works and experiments.