Correlation between structural and optical properties in proton-exchanged LiNbO3

Abstract

We present a correlation of the structural characterization of proton-exchanged LiNbO3 provided by ion beam and x-ray analysis with the optical characterization provided by refractive index and second-harmonic generation measurements. The process of proton exchange induces disorder in the crystal lattice of LiNbO3. Subsequent thermal annealing removes only partially the lattice disorder and, in particular, the near surface region of the samples generally remains highly distorted. Results of x-rays studies indicate that the proton exchange induces a strain in the lattice and thermal annealing partially recovers it.