Ferroelectric domain inversion in Ti-diffused LiNbO3 optical waveguide

Abstract

The ferroelectric domain in Ti‐diffused c‐plate LiNbO₃ optical waveguides were examined by chemical etching. In the Ti‐diffused +c layer, a domain‐inversion layer was formed where the spontaneous polarization is opposite to that of the substrate. The formation is dependent upon diffusion conditions. On the other hand, no domain inversion appeared in the diffused −c layer. It is concluded that the −c face is quite favorable for fabricating Ti‐diffused c‐plate optical waveguide for application in electro‐optic devices. A plausible explanation for the domain inversion is considered.