Abstract: A hollow cathode sputtering apparatus and related method for introducing dopants into a sputtered coating is provided. The method utilizes a sputter reactor which includes a cathode channel that allows a gas stream to flow therein and a flow exit end from which gases may flow out of and towards a substrate to be coated. The cathode channel as used in the invention is defined by a channel defining surface that includes at least one target material. The sputter reactor further includes a dopant target positioned to provide dopant atoms to the gas stream when the gas stream is flowed through the cathode channel.