Lead titanate coatings on optical fibers deposited by reactive magnetron sputtering

Abstract
A Ti/Pt/PbTiO₃/Au multilayer thin film structure has been deposited onto standard telecommunication optical fibers. A reactive magnetron sputter deposition technique at high temperature was used to obtain in situ crystallized PbTiO₃ thin films with the perovskite structure. PbTiO₃ layers with a constant thickness of about 0.81 ± 0.05 µm were obtained over a 5 cm length of fiber, but both microstructure and phase formation vary widely along the fiber length. A dielectric constant of 210 ± 13 and dielectric loss of 0.07 were measured for the phase pure PbTiO₃ coated section of fiber. Variations in the coating properties along the fiber can clearly be related to the temperature distribution occurring in the fabrication process.