Enhancement and focusing of light in nanostructured quasi-zero-refractive-index films

We present theoretical and experimental proofs that our synthesized composite material with silver nanoparticles has a quasi-zero refractive index over a wide wavelength range, and the enhanced optical transmission is observed in the material layer. The formulas of the reflectance and transmittance of a layer with a quasi-zero refractive index are consistent with the experimental data. The optical transmission is significantly enhanced by focusing the light that is scattered by the composite film.