US Patent 7347924 Anodizing of optically transmissive substrate

Metallization is disposed on at least a portion of an electrically nonconductive substrate. Plating is then disposed on the metallization, and an anodized layer of the plating is configured to provide the substrate with an anodized surface. The substrate may be glass or ceramic, and in particular sapphire. The substrate may be optically transmissive, and the metallization and plating may define a window adapted to transmit light through the substrate.