Quasi-phase matched second harmonic generation in a PMN-38PT crystal

We used an all-optical poling method to fabricate quadratic nonlinearity gratings in a tetragonal 0.62Pb(Mg_1/3Nb_2/3)O_3-0.38PbTiO_3 (PMN-38PT) crystal. We then employed these gratings in quasi-phase matched collinear second harmonic generation processes. By measuring the second harmonic output, we provided, for the first time, to the best of our knowledge, quantitative estimates of all three non-zero quadratic nonlinearity coefficients of the PMN-38PT crystal.