Epitaxial growth and characterization of stoichiometric LiNbO_(3) films prepared by the sol-gel method

摘要

After stoichiometric LiNbO_(3) thick films were deposited on z-cut LiNbO_(3) substrates using the sol-gel method from a precursor solution containing various polyvinyl alcohol (PVA) concentrations, their characteristics were investigated. The film thickness increased linearly with the increase in PVA and precursor concentrations. The orientation relationships between films and substrates were determined by x-ray diffraction, Raman spectroscopy, and transmission electron microscopy, and the results showed that (006) oriented LiNbO_(3) epitaxial layers with parallel epitaxial relationships could be grown on a z-cut LiNbO_(3) substrate. The refractive indexes of the films were n_(0)=2.28±0.02 and n_(e)=2.19±0.02 at a wavelength of 632.8 nm, and their transmission loss was 0.50±0.04 dB/cm.