A simple technique for suppressing Li2O out-diffusion in Ti : LiNbO3 optical waveguide

Abstract
Li2O out‐diffusion in Ti‐diffused LiNbO3 optical waveguide was suppressed by annealing a LiNbO3 y‐cut substrate in Li2CO3 powder prior to the Ti‐diffusion process. The waveguide, made of the substrate annealed at 600 °C for 72 h, supported single TE and TM modes without any out‐diffusion modes for 0.6328‐μm light propagation.