A coating material containing metal oxide is applied to one side of a substrate, both coating and substrate being transparent to visible light. An absorber material is placed in heat transfer proximity to the coating and a laser beam is transmitted through the substrate and through the coating to strike the absorber material at the interface between coating and absorber. The absorber material absorbs optical energy from the laser beam causing the material to heat. Heat from the absorber propagates to the coating to heat a localized region, causing the coating material to anneal. If desired, the coating material can include a doping material that fuses into the coating during annealing.