Abstract
Pulse-compression gratings for high-power, short-pulse laser systems are exposed to high electric fields that are further enhanced locally due to their 2D nanostructured surface. This makes them vulnerable to laser-induced damage. The present work considers the effect on electric-field modulation caused by an array of commonly found inadvertent flaws in gratings including fabrication defects, contamination particles, and laser-induced–damage initiation. These defects affect the laser-damage performance characteristics of the grating. To understand the local field-enhancement distribution due these imperfections, 3D modeling of the electric-field distribution is performed with a sufficiently high resolution of 1/74 of the laser wavelength (λ) while considering a volume of ≈489 λ3. The results provide estimates for the ensuing electric-field intensification and projected reduction of the laser-damage thresholds, as well as the anticipated pattern of damage growth initiation.
Funder
National Nuclear Security Administration