On the validity of the paraxial approximation for electron acceleration with radially polarized laser beams

Abstract

In the study of laser-driven electron acceleration, it has become customary to work within the framework of paraxial wave optics. Using an exact solution to the Helmholtz equation as well as its paraxial counterpart, we perform numerical simulations of electron acceleration with a high-power TM01 beam. For beam waist sizes at which the paraxial approximation was previously recognized valid, we highlight significant differences in the angular divergence and energy distribution of the electron bunches produced by the exact and the paraxial solutions. Our results demonstrate that extra care has to be taken when working under the paraxial approximation in the context of electron acceleration with radially polarized laser beams.

arXiv comment3 pages, 2 figures. Accepted for publication in Optics Letters

References in corpus (2)

• Direct acceleration of an electron in infinite vacuum by a pulsed radially-polarized laser beam
• Electron acceleration driven by ultrashort and nonparaxial radially polarized laser pulses

Cited by in corpus (8)

• Laser-Induced Linear Electron Acceleration in Free Space
• Relativistic acceleration of electrons injected by a plasma mirror into a radially polarized laser beam
• On the importance of frequency-dependent beam parameters for vacuum acceleration with few-cycle radially-polarized laser beams
• Influence of longitudinal chromatism on vacuum acceleration by intense radially polarized laser beams
• An improved beam waist formula for ultrashort, tightly-focused linearly, radially, and azimuthally polarized laser pulses in free space
• Focused fields of ultrashort radially-polarized laser pulses having low-order spatio-temporal couplings
• Efficiently parallelized modeling of tightly focused, large bandwidth laser pulses
• Maxwell-consistent, symmetry- and energy-preserving solutions for ultrashort laser pulse propagation beyond the paraxial approximation