Enhanced harmonic generation and wave-mixing via two-color multiphoton excitation of atoms/molecules

TL;DR

This paper investigates how two-color multiphoton resonant excitation can enhance harmonic generation and wave-mixing in atoms and molecules, providing analytical and numerical insights into efficient multicolor harmonic production.

Contribution

It introduces a generalized rotating wave approximation to analytically study multicolor harmonic spectra in two-color multiphoton excitation, validated by numerical calculations.

Findings

Good agreement between analytical and numerical results

Efficient generation of high multicolor harmonics demonstrated

Application to hydrogen atom and diatomic molecular ion

Abstract

We consider harmonics generation and wave-mixing by two-color multi photon resonant excitation of three-level atoms/molecules in strong laser fields. The coherent part of the spectra corresponding to multicolor harmonics generation is investigated. The obtained analytical results on the basis of generalized rotating wave approximation are in a good agreement with numerical calculations. The results applied to the hydrogen atom and homonuclear diatomic molecular ion show that one can achieve efficient generation of moderately high multicolor harmonics via multiphoton resonant excitation by appropriate laser pulses.