High-order harmonic generation driven by chirped laser pulses induced by linear and non linear phenomena

TL;DR

This paper investigates how chirped ultrashort laser pulses, generated through linear and nonlinear dispersive media, can extend high-order harmonic generation cut-offs, combining classical and quantum models for detailed physical insights.

Contribution

It provides a comprehensive analysis of the parameters affecting HHG cut-off extension using both classical and quantum approaches, which is rarely detailed in existing literature.

Findings

Chirped pulses can significantly extend HHG cut-offs.

Both linear and nonlinear media influence the chirp and HHG.

Classical and quantum models agree on the physical mechanisms.

Abstract

We present a theoretical study of high-order harmonic generation (HHG) driven by ultrashort optical pulses with different kind of chirps. The goal of the present work is perform a detailed study to clarify the relevant parameters in the chirped pulses to achieve a noticeable cut-off extensions in HHG. These chirped pulses are generated using both linear and nonlinear dispersive media.The description of the origin of the physical mechanisms responsible of this extension is, however, not usually reported with enough detail in the literature. The study of the behaviour of the harmonic cut-off with these kind of pulses is carried out in the classical context, by the integration of the Newton-Lorentz equation complemented with the quantum approach, based on the integration of the time dependent Schr\"odinger equation in full dimensions (TDSE-3D), we are able to understand the underlying physics.