Impact of Plasma Dynamics On Femtosecond Filamentation

Abstract

In this thesis we ran a series of 2D simulations of femtosecond laser pulses filamenting in air using the FDTD method, a saturable Lorentz oscillator model of air [1], and two separate models of plasma: a Drude model where the plasma density is static in space, and a particle-in-cell model where plasma is free to migrate throughout the simulation space. By comparing matched pairs of simulations, which varied in pulse size, duration, and intensity, we can gauge the impact plasma dynamics has upon the evolution of a filamenting laser pulse. From these tests we determine that, while there are some visible differences between dynamic and static plasmas, plasma dynamics do not significantly alter the evolution of the pulse.