Raising laser induced damage threshold of multilayer dielectric gratings by slanting the grating ridges

Following an analysis of the interference fringes above the plane of a high-efficiency grating, a set of systematic numerical optimizations of slanted trapezoidal gratings aiming at minimizing the maximum electric field inside the grating material was conducted. The results confirm predictions based the interference fringe analysis. The most important conclusion is that slanting the grating ridges can substantially increase the laser induced damage threshold of multilayer dielectric gratings.