OPTICAL WAVE-GUIDING IN EPITAXIAL PBTIO3 THIN-FILMS

Epitaxial lead titanate (PbTiO3) thin films on SrTiO3 (100) substrate were grown in situ by radiofrequency sputtering for optical waveguidin g applications. The crystalline quality of the PbTiO3 films deposited at 550 degrees C has been investigated through x-ray diffraction analy sis. It indicates that thin films are completely c-axis oriented (rock ing curve FWHM of 0.2 degrees for the 001 reflection). The transmissio n spectrum method has been used to measure the dispersion of the refra ctive index. At 632.8 nm, the PbTiO3 film with an (001) orientation ex hibits a refractive index of 2.61, which represents 98% of the bulk ma terial. The prism-coupling technique has been also employed to determi ne the optical attenuation in the planar waveguide. In this study, we report a low propagation loss of 2.2 +/- 0.2 dB/cm obtained in a PbTiO 3 optical waveguide. (C) 1998 Optical Society of America.