High-Efficiency Transmission Gratings Fabricated in Bulk Fused Silica

High power ultraviolet lasers are now widely used in the semiconductor industry and inertial confinement fusion research, and are finding increased application in medical therapy. Whether based on excimers or frequency converted solid-state, high power ultraviolet lasers continue to be plagued by issues of optical damage and a limited choice of optical components for beam manipulation. In particular, system performance is often limited by the damage threshold of cavity and transport mirrors. Beam transport and steering based on refractive optics are limited not by surface damage as is the case with reflective systems but instead by bulk damage induced by two photon absorption, color center formation and self-focusing. These limitations can, in principle, be overcome in many applications by the use of transmission gratings fabricated in high damage threshold, transparent materials.