Controlling polarization of attosecond pulses with plasmonic-enhanced bichromatic counter-rotating circularly polarised fields

TL;DR

This paper demonstrates how combining bichromatic counter-rotating circularly polarized fields with plasmonic-enhanced inhomogeneous fields allows control over the polarization state of attosecond pulses by selectively influencing electron trajectories during high-harmonic generation.

Contribution

It introduces a novel method to manipulate attosecond pulse polarization using plasmonic-enhanced fields combined with bichromatic circularly polarized lasers.

Findings

Selective enhancement or suppression of electron trajectories.

Modification of attosecond pulse ellipticity.

Control over sub-cycle high-harmonic generation dynamics.

Abstract

The use of bichromatic counter-rotating laser field is known to generate high-order harmonics with non-zero ellipticity. By combining such laser field with a plasmonic-enhanced spatially inhomogeneous field, we propose a way to influence the sub-cycle dynamics of the high-harmonic generation process. Using the numerical solution of the time-dependent Schr{\"o}dinger equation combined with classical trajectory Monte Carlo simulations, we show that the change of the direction and the strength of the plasmonic field selectively enhances or suppresses certain recombining electron trajectories. This in turn modifies the ellipticity of the emitted attosecond pulses.