Description
High-power laser applications demand highly robust diffractive optical elements. Standard gold-coated reflection gratings suffer from 3–5% thermal absorption, causing structural degradation under intense loads. While multilayer dielectric gratings offer higher damage thresholds, their narrow reflection bandwidth and susceptibility to vacuum delamination restrict their use in broadband ultrafast regimes. Monolithic transmission gratings etched directly into resilient dielectrics eliminate these coating failures, but conventional manufacturing relies on mask-dependent, highly complicated lithographic processes. Direct laser interference patterning offers a maskless alternative, but using ultrashort pulses is fundamentally limited by spatio-temporal chirp, which broadens pulse duration and degrades fringe contrast. We resolve these issues using an optimized Talbot interferometer configuration with UV femtosecond pulses (343 nm, 300 fs). We demonstrate high-throughput, single-step texturing, achieving a 750 nm spatial period and record aspect ratios up to 0.5 on fused silica, sapphire, and quartz, establishing a scalable manufacturing route for high-power transmission diffractive optics.
