Sol-Gel Pzt Films for Optical Waveguides

Abstract

AbstractSol-gel processing is a candidate ferroelectric thin-film deposition method for electronic and electro-optic applications. At Battelle, sol-gel PbTiO3 and Pb(Zr,Ti)O3 films have been prepared on sapphire and single-crystal SrTiO3 substrates. Films deposited and annealed on sapphire substrates are crystalline with the perovksite structure and minimal crystallographic orientation, whereas films deposited on isostructural and lattice-matched SrTiO3 substrates exhibit a high degree of orientation. Guided-mode refractive index measurements were made using a single-prism method and film indices were computed. Refractive index values measured for PbTiO3 films (n = 2.58) and PZT films (n = 2.50) were slightly lower than values expected on the basis of bulk measurements. In double-prism experiments, optical wavcguiding was achieved over distances up to 10 mm in oriented PZT films on [100] SrTiO3substrates. Optical loss of 19 dB/cm was measured on one of these film samples. Such films, given requisite improvement in optical quality, may be suitable for useful optical waveguide devices. An approach is presented for the integration of ferroelectric waveguides onto silicon and/or GaAs substrates.