Strong-field control and enhancement of chiral response in bi-elliptical high-order harmonic generation: an analytical model

TL;DR

This paper develops an analytical model to describe and enhance the chiral response in high-order harmonic generation driven by bi-elliptical laser fields, enabling control over chiroptical effects in chiral molecules.

Contribution

The paper introduces a comprehensive analytical model that explains the chiral high-order harmonic generation mechanism and demonstrates how to control and enhance the chiral response through field parameter tuning.

Findings

The model captures key features of chiral harmonic spectra.

Control of chiral response is achieved by tuning laser parameters.

Suppression of achiral background via the linear Stark effect enhances chirality.

Abstract

The generation of high-order harmonics in a medium of chiral molecules driven by intense bi-elliptical laser fields can lead to strong chiroptical response in a broad range of harmonic numbers and ellipticities [D. Ayuso et al, J. Phys. B 51, 06LT01 (2018)]. Here we present a comprehensive analytical model that can describe the most relevant features arising in the high-order harmonic spectra of chiral molecules driven by strong bi-elliptical fields. Our model recovers the physical picture underlying chiral high-order harmonic generation based on ultrafast chiral hole motion and identifies the rotationally invariant molecular pseudoscalars responsible for chiral dynamics. Using the chiral molecule propylene oxide as an example, we show that one can control and enhance the chiral response in bi-elliptical high-order harmonic generation by tailoring the driving field, in particular by tuning its frequency, intensity and ellipticity, exploiting a suppression mechanism of achiral background based on the linear Stark effect.