Growth of an epitaxial Bi4Ti3O12/CeO2/MgO heterostructure for waveguide applications

Abstract

Using pulsed laser deposition, a Bi4Ti3O12 thin film and Bi4Ti3O12/CeO2 heterostructures were grown on MgO(001) substrates. Structural properties of the film and the heterostructures were investigated using x-ray diffraction techniques. The heterosturctures were found to be more useful for making an optical single-mode waveguide, since it allows larger cut-off dimensions. By controlling the deposition temperature of the CeO2 interlayer, an epitaxial heterostructure could be grown. From the epitaxial Bi4Ti3O12/CeO2/MgO heterostructure, a ridge waveguide was fabricated by photolithographic and ion-milling techniques. A single-mode near-field pattern was observed using an end-fire coupling method.