Correlated electron dynamics in nonsequential double ionization by orthogonal two-color laser pulses

Yueming Zhou,Peixiang Lu,Aihong Tong,Qing Liao,Cheng Huang

doi:10.1364/oe.19.002301

Abstract

We have investigated the correlated electron dynamics in nonsequential double ionization (NSDI) of helium by the orthogonally polarized two-color pulses that consisted of an 800-nm and a 400-nm laser fields using the classical ensemble model. Depending on the relative phase of the two-color field, the electron momentum distributions along the polarization direction of the 800-nm field exhibit a surprisingly strong anticorrelated or correlated behavior. Back analysis reveals that recollisions eventually leading to NSDI are concentrated in a time window as short as several hundreds attoseconds with this scheme. By changing the relative phase of the two-color field, the revisit time of recolliding electron wave packet has been controlled with attosecond precision, which is responsible for the various correlated behaviors of the two electrons. Our results reveal that the orthogonally polarized two-color field can serve as a powerful tool to control the correlated electron dynamics in NSDI.

Highlights

Atoms or molecules exposed to an intense femtosecond laser pulse suffer tunneling ionization
By changing the relative phase of the two fields, the revisit time of recolliding electron wave packet can be controlled with attosecond precision
We find out the recollision time of the double ionization (DI) trajectories, where the recollision time is defined as the instant of the closest approach after the first departure of one electron from the core [16, 19]

Summary

Introduction

Atoms or molecules exposed to an intense femtosecond laser pulse suffer tunneling ionization. The recolliding electron wave packet can be exploited to produce attosecond (as) extreme ultraviolet pulses [2], to obtain an image of the electron orbital [3], or to probe molecular dynamics with attosecond resolution [4]. Via manipulating the recollision angle of the recolliding electron wave packet with the orthogonally polarized two-color field, the atomic orbital symmetry [14] as well as the molecular orbital symmetry [15] is clearly probed. By changing the relative phase of the two fields, the revisit time of recolliding electron wave packet can be controlled with attosecond precision Based on this precise control of the revisit time of recolliding electron wave packet, the two-electron momentum distributions along the polarization of the 800-nm field are manipulated to exhibit a surprisingly strong anticorrelated or correlated behavior

The classical ensemble model

Results and discussions

Conclusion