Anneal proton-exchanged planar waveguides on LiNbO3 are investigated on aspect of crystallography and of optical properties. The strains and stress on crystalline lattices of LiNbO3 due to proton exchange and annealing respective are measured by DDX (Double Diffraction of X-ray) and IR spectrometer. We study theoretically and experimentally the induced photoelastic and piezoelectric effects inside exchanged layer to explore mechanism of anneal. That demonstrates annealing technology being a efficient compensation permits to ameliorate the quality of waveguide and deduced optical propagating loss.
"Mechanism of anneal proton exchange to fabricate waveguides on LiNbO3", Proc. SPIE 2891, Integrated Optoelectronics, (30 September 1996); doi: 10.1117/12.253182; https://doi.org/10.1117/12.253182