Geometrically-Derived Anisotropy in Cubically Nonlinear Dielectric Composites

We consider an anisotropic homogenized composite medium (HCM) arising from isotropic particulate component phases based on ellipsoidal geometries. For cubically nonlinear component phases, the corresponding zeroth-order strong-permittivity-fluctuation theory (SPFT) (which is equivalent to the Bruggeman homogenization formalism) and second-order SPFT are established and used to estimate the constitutive properties of the HCM. The relationship between the component phase particulate geometry and the HCM constitutive properties is explored. Significant differences are highlighted between the estimates of the Bruggeman homogenization formalism and the second-order SPFT estimates. The prospects for nonlinearity enhancement are investigated.