Determination of the optical nonlinear coefficients signs for ZnO films and single crystal

Abstract

The epitaxial thin films and single crystals of ZnO were investigated by optical second harmonic generation (SHG). A method for characterization the optical nonlinear coefficients of ZnO are proposed. It is shown that the sign of d33 nonlinear coefficient is negative. Using the tensorial characteristic of optical SHG crystallographic orientation of noncentrosymmetric hexagonal media can be determined with an error less than ± 0.10.