Inhomogeneous microlens device for near-field focusing, beam forming, and high-efficiency far-field device implementation

Abstract

The disclosure relates to an optically-transparent device () comprising a main part () of dielectric material having a refractive index n. Such an optically-transparent device is configured for forming a field intensity distribution in a near zone of said device, from electromagnetic waves incidentally illuminating said device, when said device is embedded in a dielectric material having a refractive index nlower than said refractive index n. Said device () further comprises at least one insert () of dielectric material having a refractive index nlower than said refractive index nand different from said refractive index n, said at least one insert being inserted into said main part, and each one of said at least one insert and said main part having respectively an edge of a step formed by a base surface of said at least one insert or said main part and a lateral surface of said at least one insert or said main part, said base surface being defined with respect to an arrival direction of said electromagnetic wave. The disclosure also relates to a system comprising a plurality of above-described optically-transparent devices uniformly distributed within a dielectric host medium, so as to form a far-field device for far-field applications.