Above-threshold ionization in neon produced by combining optical and bichromatic XUV femtosecond pulses

TL;DR

This paper investigates neon ionization using combined femtosecond bichromatic EUV and infrared pulses, revealing complex angular distribution oscillations and demonstrating control of asymmetry via infrared frequency tuning.

Contribution

It introduces a combined optical and bichromatic XUV approach to control neon ionization and analyzes angular distributions with a new theoretical and computational framework.

Findings

Complex oscillations in angular anisotropy parameters with infrared intensity

Coherent control of ionization asymmetry by tuning infrared frequency

Time-dependent calculations support the strong-field approximation analysis

Abstract

We consider the ionization of neon induced by a femtosecond laser pulse composed of overlapping, linearly polarized bichromatic extreme ultraviolet and infrared fields. In particular, we study the effects of the infrared light on a two-pathway ionization scheme for which Ne 2s22p53s1P is used as intermediate state. Using time-dependent calculations, supported by a theoretical approach based on the strong-field approximation, we analyze the ionization probability and the photoelectron angular distributions associated with the different sidebands of the ionization spectrum. Complex oscillations of the angular distribution anisotropy parameters as a function of the infrared light intensity are revealed. Finally, we demonstrate that coherent control of the asymmetry is achievable by tuning the infrared frequency to a nearby electronic transition.