Nonlinear optical properties of lithium niobate crystals doped with zinс

The coefficients of the second order nonlinear optical dij tensor were calculated by the method developed on the basis of the dielectrics theory of Phillipson and Van Wetchen and the Levin charge coupling model for lithium niobate crystals doped with zinc (3.43–5.84 mol %). In LiNbO3 : Zn crystals, the concentration dependences of the nonlinear optical coefficients showed several regions with maxima and minima; the most noticeable changes in the nonlinear optical coefficients were observed at threshold concentrations of zinc oxide in the melt. Doping with zinc increases the conversion efficiency of the second harmonic radiation, such the crystals are more promising for use in nonlinear optics than a nominally pure lithium niobate crystal.