Use of spatiotemporal couplings and an axiparabola to control axial energy deposition velocity

TL;DR

This paper demonstrates an experimental method to control the axial energy deposition velocity of high-intensity laser pulses using spatiotemporal couplings and an axiparabola, enabling superluminal or subluminal energy transfer for laser-wakefield accelerators.

Contribution

It introduces a novel approach combining tunable pulse-front curvature with an axiparabola to control energy deposition velocity in laser systems.

Findings

Able to modify energy deposition velocity to be superluminal or subluminal

Experimental results align with theoretical calculations and simulations

Supports dephasingless acceleration in laser-wakefield applications

Abstract

This paper presents the first experimental realization of a scheme that allows for the tuning of the axial energy deposition velocity of a focal spot with relativistic intensity. By combining a tunable pulse-front curvature with the axial energy deposition characteristics of the axiparabola, an aspheric optical element, this system allows for controlling the dynamics of laser-wakefield accelerators. We demonstrate the ability to modify the axial energy deposition velocity of 100 TW laser pulses to be superluminal or subluminal. The experimental results are supported by theoretical calculations and simulations, strengthening the case for the axiparabola as a pertinent strategy to achieve dephasingless acceleration.