Molecular imaging using high-order harmonic generation and above-threshold ionization

TL;DR

This paper presents a novel method for molecular imaging that uses a one-to-one mapping between high-order harmonic frequencies and electron momenta, enabling accurate retrieval of molecular transition moments even with imperfect reference atoms.

Contribution

It introduces a new approach linking high-order harmonic generation and above-threshold ionization for improved molecular imaging accuracy.

Findings

Method accurately retrieves molecular transition moments.

Mapping works with very short laser pulses.

Effective even with suboptimal reference atoms.

Abstract

Accurate molecular imaging via high-order harmonic generation relies on comparing the harmonic emission from a molecule and an adequate reference system. However, an ideal reference atom with the same ionization properties as the molecule does not always exist. We show that for suitably designed, very short laser pulses, a one-to-one mapping between high-order harmonic frequencies and electron momenta in above-threshold ionization exists. Comparing molecular and atomic momentum distributions then provides the electron return amplitude in the molecule for every harmonic frequency. We show that the method retrieves the molecular recombination transition moments highly accurately, even with suboptimal reference atoms.