An optically multiplexed single-shot time-resolved probe of laser-plasma dynamics.

Z E Davidson,R J Gray,P Mckenna,S D R Williamson,D Neely,K L Lancaster,A Higginson,B Gonzalez-Izquierdo,M King,D Farley

doi:10.1364/oe.27.004416

Abstract

We introduce a new approach to temporally resolve ultrafast micron-scale processes via the use of a multi-channel optical probe. We demonstrate that this technique enables highly precise time-resolved, two-dimensional spatial imaging of intense laser pulse propagation dynamics, plasma formation and laser beam filamentation within a single pulse over four distinct time frames. The design, development and optimization of the optical probe system is presented, as are representative experimental results from the first implementation of the multi-channel probe with a high-power laser pulse interaction with a helium gas jet target.

Highlights

Laser-plasma interactions attract significant research interest in part because they offer a route to to accessing exotic states of matter, including fusion plasmas [1], and as a compact source of radiation [2]
There have been a number of recent results that highlight the sensitivity of the source properties to changes in the laser and plasma parameters within a narrow range [4,5,6]. Some of these dynamics can be elucidated in numerical simulations, due to limitations in the physical processes that can be included in codes and the use of idealized input parameters, measurements in the laboratory give the most comprehensive insights
We present the design and the first measurements of a temporally resolved laser–plasma interaction tracking the propagation of a single laser pulse using a novel multichannel probe

Summary

Introduction

Laser-plasma interactions attract significant research interest in part because they offer a route to to accessing exotic states of matter, including fusion plasmas [1], and as a compact source of radiation [2]. There presently exists a growing need for the development of experimental techniques which enable detailed and controlled investigation with high spatial and temporal resolution in order to investigate complex evolving laser–plasma dynamics such as self-focusing [7] or the propagation of higher-order modes (such as Laguerre-Gaussian beams) in plasma [8] Progress in this area will open up a new dimension of experimental measurement and provide additional capability to quantify key factors which limit the control of laser–plasma-driven radiation sources. We present the design and the first measurements of a temporally resolved laser–plasma interaction tracking the propagation of a single laser pulse using a novel multichannel probe We demonstrate that this optical probe system enables picosecond-scale temporal resolution and two-dimensional spatial resolution of a single interaction. We envisage the multi-channel probe concept to potentially enhance existing approaches to temporally resolve ultra-fast phenomena across other fields of scientific research that are inherently susceptible to stochastic phenomena [19], such as in pump-probe microscopy [24] and irreversible reaction dynamics [25]

System design

Experimental set up for use on high intensity laser–plasma interactions

Initial experimental results

Summary and outlook