Annealing effect on planar waveguides in LiNbO3 produced by oxygen ion implantation

We reported on planar waveguides in stoichiometric lithium niobate fabricated by 4.5 MeV oxygen ion implantation with a dose of 6x10(14) ions/cm(2) at room temperature. After ion implantation, these samples were annealed at 240 degrees C, 260 degrees C, and 300 degrees C for 30 min. We investigated annealing effect on the guiding modes and near-field images in the waveguides by prism-coupling method and end-face coupling method respectively. We found that for the extraordinary refractive index a positive alternation occurred in the near-surface region while a negative alternation happened at the end of ion track. Moreover, we measured the transmission spectra for the pure sample and implanted samples before and after annealed at different temperatures, and we observed an absorption peak at similar to 480nm (2.6 eV) in all of these SLN samples. (C) 2010 Elsevier B.V. All rights reserved.