Abstract: A method of preparing graphene on a SiC substrate includes bombarding a surface of the SiC substrate with ions and annealing a volume of the SiC substrate at the bombarded surface to promote agglomeration of carbon at the bombarded surface to form one or more layers of graphene at that surface. The ions can be Si, C, or other ions such as Au. The annealing can be carried out using a thermal source of heating or by irradiation with at least one laser beam or other high energy beam.

Abstract: A supported graphene device comprises at least one graphene feature of 1 to about 10 graphene layers having a predetermined shape and pattern, with at least a portion of each graphene feature being supported on a substrate. In some embodiments the device comprises graphene features supported on crystalline semiconductor substrate, such as silicon or germanium. The graphene features on a crystalline semiconductor substrate can be fabricated by forming an amorphous carbon doped semiconductor on the crystalline semiconductor substrate and then epitaxially crystallizing the amorphous semiconductor with carbon migration to the surface to form a graphene feature of one or more graphene layers. The epitaxy can be promoted by heating the device or by irradiation with a laser.

Abstract: A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO.sub.3 crystals are implanted with high concentrations of Ti dopant at ion energies of about 350 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000.degree. C. produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality single crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguides properties.