Free-electron laser without inversion in the high gain regime

Abstract

A ‘phased’ optical klystron drift region developed to obtain free-electron lasing (FEL) without inversion in the small-gain small-signal regime is here applied to the high-gain regime. Numerical simulations show improvement in the gain and the tolerance to electron beam energy spread compared to conventional FEL. Longitudinal phase space dynamics has been studied to show the effect of the drift region on the electron beam.