Guided-wave optical properties of sol-gel ferroelectric films

Abstract

Sol-gel processing methods have been used to prepare thin films of lead titanate, Pb(Zr,Ti)O3, and Pb(Mg1/3Nb2/3)O3 on sapphire and single-crystal strontium titanate substrates. These films have been characterized using x-ray diffraction, optical waveguiding measurements at 633 nm wavelength, and optical transmission measurements. The films, in general, contain a mixture of perovskite and pyrochlore phases, with perovskite formation being favored by higher processing temperatures, by use of the SrTiO3 substrates, and by the addition of excess lead precursor compound to the starting solutions. The films have refractive indices close to, but lower than, those of the corresponding bulk materials. The reduction of the refractive indices from the bulk values is believed to result primarily from incomplete densification. Transmission measurements show that the optical dispersion in the PbTiO3 films is similar to that in the bulk crystal. Although all films showed scattering losses, waveguiding over distances up to 1 cm was observed in some films. For multimode waveguides, conformity of the mode indices to those expected for a uniform guide is suggested as one test of film uniformity as a function of depth.

Synthesis, characterization, photoluminescence and ferroelectric properties of PbTiO3 nanotube arrays

“…The precursor sol was prepared as follows: 9.552 g lead acetate (Pb(OAc) 2 , AR) with 5% excess was firstly dissolved in 10 ml glacial acetic acid, and then the solution was refluxed at 60 • C under stirring for 0.5 h. The reason why 5% excess of lead is added in the precursor is to compensate the lead loss during thermal annealing. This has been widely used in the sol-gel synthesis of PTO thin films [22,32,33]. After refluxing, the solution was cooled down to room temperature.…”

Wet etching of sol-gel deposited lead lanthanum zirconate titanate for photonic crystal applications

“…[1][2][3][4][5] Depending on whether the film is ferroelectric or not, PLZT displays linear (∆n i = -1/2 n 3 r ij E j , Pockels effect) or quadratic (∆n i = -1/2 n 3 r ijk E j E k , Kerr effect) change in refractive index ∆n i when upon application of a transverse bias field E ij , with the magnitude determined by its electrooptic coefficient r ijk . PLZT of certain compositions such as PLZT 8/65/35 (x/y/1-y) exhibit high values of r ijk and good transparency on the operating wavelength, making them good candidates for intergrated electrooptic switches with low power consumption.…”

Preparation of Pb(Zr,Ti)O 3 Thin Films on Silica Substrate by Metallo-Organic Decomposition

“…In recent years, ferroelectric Pb(Zr,Ti)O 3 (PZT) thin films deposited on single crystal substrates such as Sapphire, MgO and SrTiO 3 revealed excellent electro-optic properties [1][2][3][4][5]. However, the integration of the active components with passive devices such as waveguide, coupler and array waveguide grating (AWG) on the silica substrates is extremely important for the miniaturization of planar lightwave circuits (PLC) employed in optical fiber communication.…”