Epitaxial nonlinear optical films of LiTaO3 grown on GaAs in waveguide form

Nonlinear optical films of LiTaO3 were epitaxially grown on (NH4)2Sx-treated (111) GaAs using e-beam evaporated MgO as intermediate layers. The MgO lattice was found to rotate by 180° about the [111] surface normal with respect to the GaAs substrate. The laser-ablated LiTaO3 film grew epitaxially in the preferred [0001] direction and formed a waveguide with its underlying buffer layer of MgO.