Direct-Write E-beam Submicron Domain Engineering in LiNbO_3 Thin Films Grown by Liquid Phase Epitaxy

摘要

We demonstrate submicron ferroelectric domain engineering in liquid phase epitaxy (LPE) LiNbO_3 thin films grown on LiNbO_3 and LiTaO_3 substrates using a direct-write electron beam poling for waveguide applications. LiNbO_3 thin films of several-micron thickness were grown using a flux melt of 20 mol% LiNbO_3-80 mol% Li VO_3. To engineer domain structures in Z~- oriented LPE LiNbO_3 films, a direct-write electron beam poling was implemented. It is shown that we can engineer the domain structure of LPE LiNbO_3 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 LiNbO_3 single crystal and a LPE LiNbO_3 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.