Mach-Zehnder electro-optic waveguide modulators were fabricated based on BaTiO3 (BTO)-SrTiO3 (STO) multilayer thin film stacks grown on single crystal MgO substrates by pulsed laser deposition. X-ray diffraction measurements confirmed the formation of a BTO-STO superlattice with periodicity of 11unit cells. Strip-loaded waveguides were formed by patterning a SixNy film deposited onto the BTO-STO stack while Al electrodes of 3mm length and 13μm separation were fabricated in the vicinity of the active waveguide arm of the Mach-Zehnder modulator. An effective electro-optic coefficient of 73pm∕V at 1550nm wavelength was determined for the deposited BTO-STO superlattice by measuring the output intensity as a function of applied electric field.
Hiltunen, J., Seneviratne, D., Sun, R., Stolfi, M., Tuller, H., Lappalainen, J., & Lantto, V. (2006). BaTiO3-SrTiO3 multilayer thin film electro-optic waveguide modulator. Applied Physics Letters, 89(24), 242904-242906. https://doi.org/10.1063/1.2404982