Related Experiment Video
Updated: Jun 12, 2026

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems
Published on: February 10, 2020
Frequency shift and asymmetric line shape of the fourth anti-Stokes component from a hydrogen Raman shifter
Abstract:
We have measured the spectral properties of the fourth anti-Stokes component of the output of a pressurized, molecular hydrogen, Raman shifter pumped by the intense output of a frequency-doubled narrowband pulsed dye laser. All the observed line shapes are asymmetric, with full widths at half-maximum ranging from 0.3 to 0.8 cm(-1). The spectral peak of the Raman-shifted light varies linearly with the intensity of the pump light and is given by sigma(rho,I) = sigma(rho) + AI. The previously measured density-dependent Stokes shift is sigma(rho), the intensity of the laser is I, and A is 1.5 +/- 0.2 cm(-1)/(TW/cm(2)). The electric field-induced shift and asymmetric line shape limit the accuracy and resolution of spectroscopic measurements made with light from a hydrogen Raman shifter. We propose that these observations may be explained by the ac Stark effect in the Raman shifting medium.
Related Concept Videos
NMR Spectroscopy: Chemical Shift Overview
For instance, the proton...
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...
Inductive Effects on Chemical Shift: Overview

