Electron acceleration driven by ultrashort and nonparaxial radially polarized laser pulses

TL;DR

This paper demonstrates that ultrashort, nonparaxial radially polarized laser pulses can efficiently accelerate electrons in vacuum, achieving high energy gains with current laser technology by using tighter focus and single-cycle pulses.

Contribution

It provides exact solutions to Maxwell's equations showing how tighter focus and pulse duration enhance electron acceleration, surpassing previous energy gain limits.

Findings

Tighter focus reduces the threshold power for acceleration.

Electrons can reach about 80% of the energy gain limit.

High energy gains are achievable with current laser technology.

Abstract

Exact closed-form solutions to Maxwell's equations are used to investigate the acceleration of electrons in vacuum driven by ultrashort and nonparaxial radially polarized laser pulses. We show that the threshold power above which significant acceleration takes place is greatly reduced by using a tighter focus. Moreover, electrons accelerated by tightly focused single-cycle laser pulses may reach around 80% of the theoretical energy gain limit, about twice the value previously reported with few-cycle paraxial pulses. Our results demonstrate that the direct acceleration of electrons in vacuum is well within reach of the current laser technology.