Enhanced Pulse-Compression from Tunnel-Ionized Plasma Interactions with a Laser Pulse

Abstract

The self-compression of a relativistic Gaussian laser pulse propagating in a double ionized Helium gas is investigated. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> The numerical model is formulated by solving nonlinear Schrödinger equation using paraxial like approach. The beam width parameter and pulse width parameter are to investigate the laser pulse advances in the plasma. Transverse focusing and longitudinal compression in plasma is examined by characterizing beam spot size in space and time. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> This mathematical model studies intensity profile of the laser pulse including gas ionization processes, relativistic mass variation and ponderomotive effects. The results show that the including double-step ionization of Helium gas enhances the pulse compression and consequently the self-focusing of the laser pulse. The compression mechanism and the localization of the pulse intensity is boosted by the modified electron density via dielectric function. We observed the generation of short and intense laser pulses in our findings. The intense short laser pulse is particularly relevant in the development of laser-plasma accelerators.