Nondipole photoelectron momentum shifts in strong-field ionization with mid-infrared laser pulses of long duration

TL;DR

This paper investigates nondipole effects in strong-field ionization with long-duration mid-infrared laser pulses, revealing shifts in electron momentum distributions and population redistributions caused by nondipole interactions.

Contribution

It demonstrates how nondipole effects cause measurable shifts and redistributions in electron momentum spectra during long-pulse strong-field ionization.

Findings

Nondipole effects cause shifts in electron momentum rings.

Redistribution of continuum population occurs due to nondipole interactions.

Shifts are observed in the plane of propagation and polarization directions.

Abstract

We consider atomic strong-field ionization in the long-pulse limit for linearly polarized infrared laser fields. We show how nondipole effects in the plane formed by the propagation and polarization directions lead to (i) a shift of the origin of the rings describing the energetically allowed final electron momenta for individual above-threshold ionization channels and (ii) a redistribution in the continuum population on each ring.