Modeling and experimental update on quasi-phase matched direct laser electron acceleration in density-modulated plasma waveguides

Direct laser acceleration (DLA) of electrons using the axial electric field of a radially polarized, guided intense laser pulse has the potential to lead to compact laser driven accelerators for security and medical applications. A density-modulated plasma waveguide could be applied to extend the laser beam propagation distance and to achieve quasi-phase matching (QPM) between laser and electron pulses for efficient DLA. We conducted numerical simulations to design the appropriate plasma structure of the waveguide and investigate the properties of accelerated electron beams. An all-optical method, based on the igniter-heater scheme for plasma waveguide fabrication, is experimentally implemented to machine the densitymodulated plasma waveguides with low-Z gas targets. A novel angle-multiplexed diagnostic technique has been developed to extract the polarization state and temporal characteristics of a radially polarized femtosecond laser pulse using spatial-spectral interferometry. The goal of this work is to characterize the propagation of femtosecond radially polarized pulses in plasma waveguide, thus better predicting the DLA performance.