TI-DIFFUSION LINBO3 OPTICAL WAVEGUIDE AND ITS MANUFACTURE

摘要

PURPOSE:To reduce the propagation loss by making the roughness RMAX of the surface of an LiNbO3 substrate which contains diffused Ti <=0.03 mum. CONSTITUTION:The surface roughness RMAX of the LiNbO3 substrate 1 including a Ti layer diffused in a Ti-diffused LiNbO3 optical waveguide 3 obtained by diffusing thermally the Ti layer 2 patterned on the surface of an LiNbO3 sub strate 1 is set to <=0.03 mum. Namely, the surface of the substrate 1 where the optical waveguide 3 is formed is polished after the diffusion processing to improve the surface properties. Thus, the surface of the optical waveguide 3 is made smooth to prevent propagated light from being diffused by the surface and its propagation loss is reduced.