Plasma Lenses for Relativistic Laser Beams in Laser Wakefield Accelerators

TL;DR

This paper proposes a plasma lens that uses laser self-focusing to flexibly resize petawatt laser beams, reducing costs and enabling adjustable focusing for laser wakefield accelerators.

Contribution

Introduction of a plasma lens system that adjusts laser focus by leveraging self-focusing, acting as an adjustable eyepiece for laser beam resizing.

Findings

Enables flexible laser beam resizing with plasma lens.

Reduces cost and complexity of focusing systems.

Facilitates adjustable focal spot parameters for experiments.

Abstract

Focusing petawatt-level laser beams to a variety of spot sizes for different applications is expensive in cost, labor and space. In this paper, we propose a plasma lens to flexibly resize the laser beam by utilizing the laser self-focusing effect. Using a fixed conventional focusing system to focus the laser a short distance in front of the plasma, we can adjust the effective laser beam waist within a certain range, as if a variety of focusing systems were used with the plasma lens acting as an adjustable eyepiece in a telescope. Such a setup is a powerful tool for laser wakefield accelerator experiments in state-of-art petawatt laser projects and allows for scanning focal spot parameters.