Direct-Write E-beam Submicron Domain Engineering in LiNbO3 Thin Films Grown by Liquid Phase Epitaxy

ABSTRACTWe demonstrate submicron ferroelectric domain engineering in liquid phase epitaxy (LPE) LiNbO3 thin films grown on LiNbO3 and LiTaO3 substrates using a direct-write electron beam poling for waveguide applications. LiNbO3 thin films of several-micron thickness were grown using a flux melt of 20 mol% LiNbO3-80 mol% LiVO3. To engineer domain structures in Z- oriented LPE LiNbO3 films, a direct-write electron beam poling was implemented. It is shown that we can engineer the domain structure of LPE LiNbO3 films by using direct e-beam poling, even though the domain orientations of the film and the substrate are opposite. We also compared e-beam poling behavior in a congruent LiNbO3 single crystal and a LPE LiNbO3 film. Using the same e-beam scan parameters, a much enhanced domain structure is obtained in LPE films. Defect structure and composition effects are also discussed.