Optical ridge waveguides in SBN crystal produced by low-dose carbon ion implantation followed by a sputter etching technique

This paper demonstrates, for the first time, a method to fabricate optical ridge waveguides in SBN photorefractive crystal, i.e. by first using high-energy carbon ion implantation (forming planar waveguide substrate) followed by Ar+ ion sputter etching (constructing ridged stripes). A two-dimensional (2D) cross-sectional refractive index profile of ridge waveguide is reconstructed by carefully considering the ridged topography as well as the index distributions of the planar waveguide. Based on this profile, the waveguide modes are calculated, in which shows a reasonable agreement with the experimentally observed modal near-field intensity distributions.