Surface plasmon enhancement of an optical anisotropy in porous silicon/metal composite

We report on the theoretical results obtained by applying the modified effective medium theory to a composite material consisting of mesoporous Si on (110)-oriented substrate with pores filled with silver through, e.g., electroplating process. The theory developed permits a self-consistent determination of the effective dielectric permittivity tensor of such materials. It is shown that the optical anisotropy of such a composite can be greatly enhanced at some wavelength ranges. While this anisotropy is generally uniaxial as in non-metal-filled mesoporous Si etched on (110) substrate, the “sign” of the anisotropy (i.e., positive or negative) changes in some portions of the spectrum. The optimum material parameters for an experimental observation of the theoretically predicted effects are determined.