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 electron accelerators, when compared to traditional near-IR laser drivers operating at 0.8–1 μm central wavelength (λlaser), as the necessary vector potential (a0) for electron injection can be achieved with smaller laser powers due to the linear dependence on λlaser. In this work, we perform 2D PIC simulations on LWFA using few-cycle, high power (5–15 TW) laser systems with λlaser ranging from 0.88 to 10 μm. Such few-cycle systems are currently under development, aiming at Gas High Harmonics Generation applications, where the favorable λlaser2 scaling extends the range of the XUV photon energies. We keep a0 and ne∕ncr (ne being the plasma density and ncr the critical density for each λlaser) as common denominators in our simulations, allowing for comparisons between drivers with different λlaser, 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.