Laser-induced damage thresholds of ultrathin targets and their constrain on laser contrast in laser-driven ion acceleration experiments

TL;DR

This study measures laser-induced damage thresholds of ultrathin foils and discusses how these thresholds limit laser contrast in ion acceleration experiments, revealing material-dependent damage behaviors.

Contribution

It provides the first comprehensive measurement of LIDTs for various ultrathin targets across different pulse durations and analyzes their impact on laser contrast constraints.

Findings

Ultrathin foils have lower damage thresholds than bulk materials.

Wide band gap dielectrics exhibit higher damage thresholds than semiconductors and conductors.

Damage mechanisms vary among different target materials.

Abstract

Single-shot laser-induced damage threshold (LIDT) measurements of multi-type free-standing ultrathin foils were performed in vacuum environment for 800 nm laser pulses with durations {\tau} ranging from 50 fs to 200 ps. Results show that the laser damage threshold fluences (DTFs) of the ultrathin foils are significantly lower than those of corresponding bulk materials. Wide band gap dielectric targets such as SiN and formvar have larger DTFs than those of semiconductive and conductive targets by 1-3 orders of magnitude depending on the pulse duration. The damage mechanisms for different types of targets are studied. Based on the measurement, the constrain of the LIDTs on the laser contrast is discussed.