Control of recollision wave packets for molecular orbital tomography using short laser pulses

TL;DR

This paper demonstrates how short, phase-stabilized laser pulses can control electron recollision directions in high-order harmonic generation, enabling improved molecular orbital tomography.

Contribution

It introduces a method to manipulate electron recollision angles using carrier-envelope phase adjustments in ultrashort laser pulses.

Findings

Recollision from one side can be achieved with phase control.

Harmonic spectra reflect semi-classical electron distributions.

Broad energy spectrum maintained during control.

Abstract

The tomographic imaging of arbitrary molecular orbitals via high-order harmonic generation requires that electrons recollide from one direction only. Within a semi-classical model, we show that extremely short phase-stabilized laser pulses offer control over the momentum distribution of the returning electrons. By adjusting the carrier-envelope phase, recollisions can be forced to occur from mainly one side, while retaining a broad energy spectrum. The signatures of the semi-classical distributions are observed in harmonic spectra obtained by numerical solution of the time-dependent Schr\"{o}dinger equation.