Viability of focusing effect by left-handed stacked subwavelength hole arrays

In this work we present advances in the design of lenses based on left-handed extraordinary transmission metamaterials which provide high transmission and focusing despite the subwavelength size of their constituent apertures. Due to the effective negative index of refraction of the close-stack of subwavelength hole arrays, concave profiles are required for focusing instead of the convex geometries of dielectric lenses. An analysis of the foci produced by plano- and bi-concave lens is carried out.