Optical waveguide fabrication by stoichiometric implantation of Ti and O into LiNbO3

X-cut substrates of LiNbO3 have been implanted at 500 degrees C with Ti and O to doses of 2.5 and 7.5 x 1017 ions/cm2, respectively. The high substrate temperature during implantation ensures dynamic recrystallization, preserving the crystallinity of the LiNbO3. The stability of the stoichiometric implants is enhanced sufficiently that annealing at 1000 degrees C proceeds with no surface degradation of the substrate. Annealing under identical conditions without the O implant usually results in phase separation of an oxide at the surface, even when annealing is performed immediately following implantation. Samples implanted with Ti and O to preserve the stoichiometric metal:oxygen ratio of the substrate can be stored at room temperature for several months without phase separation. Planar optical waveguides have been produced by stoichiometric implantation followed by annealing in water-saturated oxygen for one hour at temperatures of 900 and 1000 degrees C