Third-harmonic generation via laser-plasma interaction: Beyond the low-density approximation

Abstract

We study the third harmonic generation via laser interaction with a cold homogeneous plasma, in the one-dimensional approximation. We consider moderate values of the electron plasma density such that the pump laser pulse propagates inside the plasma without changing its shape. Our laser model allows for a finite spectral linewidth, which leads to a damping of the oscillatory behaviour of the third-harmonic power conversion rate as a function of the normalized plasma density, even for very low densities.