DEGRADATION OF THE 2ND-ORDER OPTICAL NONLINEARITY IN CUBIC MEDIA BY STRAIGHT DISLOCATIONS

The influence of straight dislocations on the second order nonlinear o ptical susceptibility chi((2)) of cubic noncentrosymmetric media has b een modeled. The resulting degradation of chi((2)) has been evaluated for screw and edge dislocations in GaAs. It is found that single screw and edge dislocations reduce the chi((2)) of GaAs by a third and simi lar to 60%, respectively. This implies that second order nonlinear opt ical effects are very sensitive to misfit dislocation generation in ep itaxially grown noncentrosymmetric media and that dislocation-free epi layers are required to realize the optimum chi((2)). (C) 1995 American Institute of Physics.