Femtosecond Spectroscopy with Vacuum Ultraviolet Pulse Pairs

TL;DR

This paper presents a novel femtosecond spectroscopy technique using vacuum ultraviolet pulse pairs generated by high-order harmonics, enabling high time resolution and spatial precision for gas-phase molecular experiments.

Contribution

It introduces a two-color high-order-harmonic method with variable delay for pump-probe experiments, demonstrating its effectiveness in resolving molecular dynamics.

Findings

Time resolution <44 fs achieved

Spatial focus profile of 4 μm x 12 μm demonstrated

Time-resolved observation of hydrogen elimination from C2H4

Abstract

We combine different wavelengths from an intense high-order harmonics source with variable delay at the focus of a split-mirror interferometer to conduct pump-probe experiments on gas-phase molecules. We report measurements of the time resolution (<44 fs) and spatial profiles (4 {\mu}m x 12 {\mu}m) at the focus of the apparatus. We demonstrate the utility of this two-color, high-order-harmonic technique by time resolving molecular hydrogen elimination from C2H4 excited into its absorption band at 161 nm.