Apparatus and method for a diamond substrate for a multi-layered dielectric diffraction grating

The present invention provides a method and apparatus for fabricating a grating on a silicon substrate, and the resulting grating device. In some embodiments, the apparatus method includes providing a silicon substrate; growing a diamond layer on the substrate; removing most of the silicon substrate and polishing an obverse face of the silicon to leave a very thin layer of polished silicon on the diamond layer; depositing a stack on the diamond layer, wherein the stack includes a plurality of pairs of dielectric layers on the thin layer of polished silicon, wherein each pair of the plurality of pairs of dielectric layers includes a first layer having a first index of refraction value and a second layer having a second index of refraction value that is different than the first index of refraction value; and forming a diffraction grating on an outer surface of the stack.