Optical antireflection of a medium by nanostructural layers

Abstract

This work examines reflection of a light from a semi-infinite medium which is modified with an ordered monolayer of spherical nanoparticles placed on or under its surface. We derive analytical expressions for the electric fields within and outside such structures and verify them with help of strict numerical simulations. We show that nanoparticles layer acts as an imaginary zero-thickness surface having complicated non-Fresnel reflection coefficients with wavelength dependent phase shift. It is shown that such monolayers may reduce reflection relative to reflection from a pure substrate surface. We derive and analyse a zero-reflection condition in the simple intuitive form. It is shown that a single layer of nanocavities near the medium-vacuum interface may increase the transparency of a dielectric medium to values close to 100% in a wide wavelength range.