Optical properties of metamaterials based on porous semiconductors and nanocomposites : theoretical considerations and experiments

Metamaterials offer a unique opportunity to engineer optical properties at will. This work was devoted to the exploration and investigation of optical properties of metamaterials and for practical realization of optical devises based on metamaterials. Particularly, a complete theory of light propagation through ordered thick macroporous silicon arrays was developed. An improved effective medium theory was developed for calculations of effective dielectric constants of porous semiconductors and applied to the explanation and identification of types of optical anisotropies in several porous semiconductor materials and composite materials made on the basis of porous silicon. Based on the theoretical formalism developed, it was shown that porous Silicon in various geometries and morphologies can be used for following novel optical elements: mesoporous Si far IR filters; mid and far IR macroporous Si filters; Macroporous Silicon UV Filters; Polarization components for the UV range; Retroreflection suppression plates; Omnidirectional IR and visible wavelengths filters. A modified effective medium approximation was developed that accounts for higher order interactions between metal nanoparticles in metal-dielectric composite materials for medium and near-percolation metal concentrations. The magneto-optical effects in metal-dielectric nanocomposite materials have been analyzed at low, medium, and near-percolation metal concentrations. The predicted magneto-optical enhancement factors were compared with electromagnetic field enhancement factors.