Accurate retrieval of structural information from laser-induced photoelectron and high-harmonic spectra by few-cycle laser pulses

TL;DR

This paper demonstrates that high-energy electron and harmonic spectra generated by few-cycle laser pulses can accurately reveal atomic and molecular structures, enabling ultrafast imaging with femtosecond resolution.

Contribution

It establishes a method to extract differential scattering and recombination cross sections from laser spectra, facilitating ultrafast molecular imaging.

Findings

Accurate extraction of scattering and recombination cross sections from spectra.

Potential for ultrafast imaging of transient molecules.

Use of existing few-cycle infrared lasers for structural analysis.

Abstract

By analyzing ``exact'' theoretical results from solving the time-dependent Schr\"odinger equation of atoms in few-cycle laser pulses, we established the general conclusion that differential elastic scattering and photo-recombination cross sections of the target ion with {\em free} electrons can be extracted accurately from laser-generated high-energy electron momentum spectra and high-order harmonic spectra, respectively. Since both electron scattering and photoionization (the inverse of photo-recombination) are the conventional means for interrogating the structure of atoms and molecules, this result shows that existing few-cycle infrared lasers can be implemented for ultrafast imaging of transient molecules with temporal resolution of a few femtoseconds.