Numerical investigation of the plasma formation in air generated by 355 nm Nd:YAG laser pulses

Abstract

In the present work, a numerical analysis is performed to investigate the comparative contribution of the mechanisms responsible for electron gain and losses in laser-induced breakdown. In this regard, we adopted a simple theoretical formulation relying on the numerical solution of a rate equation that describes the growth of the electron density due to the joined effect of multiphoton and cascade ionization processes. The rate equation also includes the effect of electron loss due to diffusion, attachment and recombination processes. The analysis considered atmospheric air irradiated by a Nd:YAG laser radiation at a wavelength of 355 nm with 5 ns pulse duration full-width half-maximum (FWHM).

Keywords

• laser-induced breakdown
• numerical calculation
• free electron density