This document discusses, among other things, a waveguide including a first metal having an outer surface proximate a dielectric material and an inner surface defining a path of the waveguide, a method of receiving an optical signal at the inner surface of the waveguide and transmitting the optical signal along at least a portion of the path of the waveguide. A method of integrating a waveguide in a substrate includes depositing sacrificial metal on a first surface of a carrier substrate to form a core of the waveguide, depositing a first metal over the sacrificial metal and at least a portion of the first surface of the carrier substrate, forming an outer surface of the waveguide and a conductor separate from the sacrificial metal, and depositing dielectric material over the first surface of the carrier substrate about the conductor.