Disentangling intra-cycle interferences in photoelectron momentum distributions using orthogonal two-colour laser fields

TL;DR

This paper demonstrates how orthogonal two-colour laser fields can disentangle quantum pathways in multiphoton ionization, revealing new interference effects in photoelectron momentum distributions influenced by phase control.

Contribution

It introduces a novel method using OTC laser pulses to separate quantum paths and uncovers previously unobserved phase-dependent interferences in photoelectron distributions.

Findings

Discovered a new interference pattern in photoelectron momentum distributions.

Showed the interference depends strongly on the relative phase of OTC pulses.

Identified quantum pathways from non-adjacent quarter cycles as the cause.

Abstract

We use orthogonally polarized two-colour (OTC) laser pulses to separate quantum paths in multiphoton ionization of Ar atoms. Our OTC pulses consist of 400~nm and 800~nm light at a relative intensity ratio of 10:1. We find a hitherto unobserved interference in the photoelectron momentum distribution, which exhibits a strong dependence on the relative phase of the OTC pulse. Analysis of model calculations reveal that the interference is caused by quantum pathways from non-adjacent quarter cycles.