Annealed proton-exchanged planar lithium tantalate waveguides fabricated in concentrated and diluted pyrophosphoric acid

Abstract

Lithium tantalate is a promising substrate for electro-optical integrated-optical devices because of its low sensitivity to optical damage and its high electro-optic coefficient. The annealed proton-exchange technique[1] (APE), which includes an additional annealing step after proton-exchange, is being established as a reliable method for producing stable, low-loss devices with little reduction in the electro-optic constant (from the bulk value). For the optimal design and fabrication of APE waveguide devices, accurate characterization data are necessary.