Temporal Feedback Control of High-Intensity Laser Pulses to Optimize Ultrafast Heating of Atomic Clusters

TL;DR

This paper demonstrates how active feedback control using genetic algorithms can optimize high-intensity laser interactions with atomic clusters, significantly increasing x-ray yields by tailoring laser pulse shapes without detailed prior knowledge.

Contribution

It introduces a novel feedback-based optimization method for high-power laser-cluster interactions, enhancing radiation output through temporal pulse shaping.

Findings

Approximately doubled x-ray energy yield.

Optimized pulses had a slow rising edge.

Effective control without detailed cluster dynamics knowledge.

Abstract

We describe how active feedback routines can be applied at limited repetition rate (5 Hz) to optimize high-power $>10$ TW) laser interactions with clustered gases. Optimization of x-ray production from an argon cluster jet, using a genetic algorithm, approximately doubled the measured energy through temporal modification of the 150 mJ driving laser pulse. This approach achieved an increased radiation yield through exploration of a multi-dimensional parameter space, without requiring detailed a priori knowledge of the complex cluster dynamics. The optimized laser pulses exhibited a slow rising edge to the intensity profile, which enhanced the laser energy coupling into the cluster medium, compared to the optimally compressed FWHM pulse (40 fs). Our work suggests that this technique can be more widely utilized for control of intense pulsed secondary radiation from petawatt-class laser systems.