Barium strontium titanate (Ba0.7Sr0.3TiO3, abbreviated as BST) thin films were grown on MgO (001) single crystal substrates using pulsed laser deposition. A hetercepitaxial growth relationship of < 001 > BST // < 001 > (MgO) was confirmed by X-ray diffraction. The bidimensional structure of a rib waveguide was designed using the effective index method. A BST/MgO rib waveguide was fabricated using photolithography and reactive ion etching techniques. A single-mode near-field output pattern was observed using an end-fire coupling method at a wavelength of 1550 nm, which is consistent with our numerical calculation. (c) 2006 Elsevier B.V. All rights reserved.