Extended propagation of powerful laser pulses in focusing Kerr media

TL;DR

This paper explores how incoherent laser pulses can travel longer distances in focusing Kerr media by counteracting wave scattering with refractive index fluctuations, enabling advanced random laser applications.

Contribution

It introduces a method to extend laser pulse propagation by using transverse heating to counter 4-wave scattering limitations.

Findings

Propagation distances significantly extended

Feasibility of ultra-powerful random lasers in plasmas

Counteracting wave accumulation enhances laser stability

Abstract

Powerful incoherent laser pulses can propagate in focusing Kerr media much longer distances than can coherent pulses, due to the fast phase mixing that prevents transverse filamentation. This distance is limited by 4-wave scattering, which accumulates waves at small transverse wavenumbers, where phase mixing is too slow to retain the incoherence and thus prevent the filamentation. However, we identify how this theoretical limit can be overcome by countering this accumulation through transverse heating of the pulse by random fluctuations of the refractive index. In these new regimes, the laser pulse propagation distances are significantly extended, making feasible a new class of random lasers, in particular, ultra-powerful random lasers in plasmas.