LATTICE-CONSTANTS OF THE PROTON-EXCHANGED WAVE-GUIDES FORMED ON DOMAIN-INVERTED LITAO3

The lattice constants in the proton-exchanged waveguide layers formed on the LiTaO3 substrate with and without the domain-inverted structure are determined with the X-ray rocking curve method. The increase in l attice constant caused by the proton-exchange process (DELTAc/c) is 0. 53%. The values DELTAc/c measured in the annealed proton-exchanged wav eguides with domain-inverted slab structure, with the periodically dom ain-inverted structure, and without the domain-inverted structure are 0.19%, 0.21% and 0.23%, respectively.