Super collimation of the radiation by a point source in a uniaxial wire medium

TL;DR

This paper demonstrates that a uniaxial wire medium can super-collimate radiation from a dipole, resulting in non-diffractive, highly directed emission with enhanced radiated power due to high photonic density of states.

Contribution

It provides an analytical framework showing super-collimation and power enhancement of dipole radiation in uniaxial wire media, a novel insight into nanowire array photonics.

Findings

Radiation pattern exhibits a singularity and is non-diffractive in the broadside direction.

Radiated power is significantly enhanced compared to dielectric host.

Analytical formula for the radiated power is derived.

Abstract

We investigate the radiation properties of a short horizontal dipole embedded in a uniaxial wire medium. It is shown that the uniaxial wire medium enables a super-collimation of the dipole radiation such that the radiation pattern has a singularity and the radiated fields are non-diffractive in the broadside direction. We derive a closed analytical formula for the power radiated by the dipole. Our theory demonstrates that as a consequence of the ultrahigh density of photonic states of the nanowire array, the power radiated by the dipole is strongly enhanced as compared to that emitted in the dielectric host material.