Laser wakefield acceleration with high-power, few-cycle mid-IR lasers

Abstract

The study of laser wakefield electron acceleration (LWFA) using mid-IR laser drivers is a promising path for future laser driven electronaccelerators, when compared to traditional near-IR laser drivers uperating at 0.8-1 {\mu}m central wavelength ({\lambda}laser), as the necessary vector potential a_0 for electron injection can be achieved with smaller laser powers due to the linear dependence on {\lambda}laser. In this work, we perform 2D PIC simulations on LWFA using few-cycle high power (5-15 TW) laser systems with {\lambda}laser ranging from 0.88-10 {\mu}m. Such few-cycle systems are currently under development, aiming at Gas High Harmonics Generation applications where the favourable {\lambda}laser^2 scaling extends the range of XUV photon energies. We keep a_0 and n_e/n_cr (n_e being the plasma density and n_cr being the critical density for each {\lambda}laser) as common denominators in outr simulations, allowing for comparisons between drivers of different {\lambda}laser, with respect to the accelerated electron beam energy, charge, and conversion efficiency. While the electron energies are mainly dominated by the plasma dynamics, the laser to electron beam energy conversion efficiency shows significant enhancement with longer wavelength laser drivers.