Fabrication of optical waveguiding layer in LiTaO3 by Cu diffusion

Abstract

Thermal diffusion and electrodiffusion of Cu into LiTaO3 have been investigated. By an appropriate choice of diffusion conditions, a single-mode waveguiding layer has been fabricated using the electrodiffusion method. The refractive-index change at the surface is 5×10−3 for both ne and no and the diffusion depth is about 4 μm. The layer supports only the fundamental modes TE0 and TM0, and exhibits good waveguiding properties.