Effect of nonlinearity in the pass-through optics on femtosecond laser filament in air

TL;DR

This paper investigates how nonlinear effects in pass-through optics influence femtosecond laser filamentation in air, revealing that phase modulation from dielectric plates affects filament onset and plasma channel length.

Contribution

First combined experimental and numerical analysis of pass-through optics' nonlinear effects on femtosecond laser filamentation in air.

Findings

Pass-through dielectric plates induce phase modulation via the Kerr effect.

Phase modulation reduces filament onset distance.

It increases plasma channel length.

Abstract

An influence of pass-through optics on femtosecond laser pulse filamentation in ambient air is analyzed for the first time both experimentally and numerically. Propagation of high-power femtosecond laser pulse through solid optical elements introduces spatiotemporal phase modulation due to the Kerr effect. This modulation may have a strong ef-fect on the pulse filamentation in air. We demonstrated that the phase modulation obtained in the thin pass-through dielectric plate reduces the distance to the filament onset and increases the plasma channel length