Vectorial analysis of a surface plasmon mode diffracted by a thick dielectric lens

Abstract

Using the vectorial form of the Huygens–Fresnel principle, we have studied the diffraction of a surface plasmon mode propagating on a metal–dielectric interface as it passes through a dielectric thick lens. This method, unlike the scalar diffraction theory, provides the interference and focusing patterns of the surface mode in the near field. Also, we have calculated the phase delay of the surface plasmon mode behind the lens without using the thin lens assumption. Based on the developed equations, we have analyzed the effects of lens thickness and aperture size on in-plane focusing of the surface plasmon.