Theoretical and experimental study of passive spatiotemporal shaping of picosecond laser pulses

Abstract

We report the results of theoretical and experimental studies on passive spatiotemporal shaping of cw mode-locked picosecond laser pulses for driving the photocathode of a high-brightness, high-current energy recovery linear accelerator. The temporal pulse shape is modified using birefringent crystals, while a refractive optical system is used to generate a flattop spatial beam profile. An optical transport system is designed and implemented to deliver the flattop pulse onto a photocathode sited 9 m away from the shapers. The alignment tolerances on the beam shaper and the temporal pulse stacker have been studied both theoretically and experimentally. The experimental results agree well with theoretical simulations. © 2009 The American Physical Society.