Characterization of the phase structure of proton exchanged channel waveguides in Z cut LiNbO3 using wet etching technique

• Wet etching is a tool for study of proton-exchange layer structure.
• Proton-exchange waveguide on Z cut of LiNbO3 consists of three phases.
• Ratio of etch rates of these three layers is approximately 4:2:1.

We report the results of a systematic study of the structure of channel waveguides fabricated on Z cut LiNbO3 in benzoic acid melt. It was found that the proton-exchange region consists of three phases of HxLi1−xNbO3 solid solution.