4-(N,N-DIMETHYLAMINO)-3-ACETAMIDONITROBENZENE SINGLE-CRYSTALS FOR NONLINEAR-OPTICAL APPLICATIONS

High-quality single crystals of 4-(NN-dimethylamino)-3-acetamidonitrobenzene (DAN) were grown from dimethylsulfoxide solutions. Crystal platelets with dimensions as large as 10 mm × 5 mm × 2 mm were produced and optically characterized. An interferometric method for the measurement of refractive indices of platelike samples was developed and used for platelet surfaces parallel to one principal axis of the indicatrix. Dispersion data of the refractive indices and the birefringence were used to calculate the optical angle and the propagation directions for phase-matched frequency doubling of Nd:YAG laser radiation as well as the dependence of phase-matching angles in the x-z plane on different wavelengths. Loci of directions for type I and type II collinear phase-matched secondharmonic generation were predicted and experimentally verified. By measuring the effective nonlinear-optical susceptibilities in several phase-matched configurations we were able to evaluate all different nonlinear-optical susceptibility coefficients allowed by Kleinman’s symmetry, the highest one being d23 = (50±15) pm/V with Miller’s coefficient δ23 = (0.49 ± 0.1) m2/As. © 1990 Optical Society of America.