Optical responses through dilute anisotropic composites: Numerical calculations via Green's-function formalism

We investigate the linear and nonlinear optical responses of dilute anisotropic networks using the Green's-function formalism (GFF)[Gu Y et al. 1999 Phys. Rev. B 59 12847]. For the different applied fields, numerical calculations indicate that a large third order nonlinear enhancement and a broad infrared absorption arise from the geometric anisotropy. It is also shown the overlap and separation between the absorption peak and nonlinear enhancement peak when the applied field is parallel, perpendicular to the anisotropy respectively. In terms of the inverse participation ratios (IPR) with q=2 and spectral distribution of optical responses, the results can be understood.