Raising the laser induced damage threshold of multilayer dielectric gratings by slanting the grating ridges: experimental verification.

In a recent Letter [Opt. Lett.51, 1347 (2026)10.1364/OL.587829], it was theoretically predicted that, besides having appropriate groove depth and duty cycle, slanting the ridges of a multilayer dielectric grating a pre-determined moderate angle away from the incident light beam can substantially increase the grating's laser-induced damage threshold. We have experimentally verified this prediction. We also have proven that it is feasible to achieve the required slanted grating profile in silica by oblique-incident reactive ion-beam etching through a pure photoresist grating mask.