Structural characterization of proton exchanged LiNbO3 optical waveguides

Abstract
This paper reports the results of structural analysis of proton‐exchanged lithium niobate optical waveguides fabricated in Z‐, X‐, and Y‐cut substrates immersed in pure benzoic acid. Rutherford backscattering spectrometry, nuclear reactions, secondary ion mass spectrometry, scanning electron microscopy, and x‐ray diffraction were used to measure atomic composition profiles and the marked lattice distortion induced by the proton exchange process in the waveguiding layer. H and Li concentration measurements indicate an exchange of about 70% of the Li atoms are present in the virgin LiNbO3 crystal.