Electromagnetic beam modulating through transformation optical structures

TL;DR

This paper demonstrates how transformation optics can be used to design devices that modulate electromagnetic beams, such as changing beam width or direction, using coordinate transformation techniques and full wave simulations.

Contribution

It introduces a finite-embedded coordinate transformation method for designing beam modulating devices in both Cartesian and cylindrical coordinates.

Findings

Beam width of Gaussian wave can be modulated by a slab.

Propagation direction of omni-directional source can be controlled.

Designs are validated through full wave electromagnetic simulations.

Abstract

The transformation media concept based on the form-invariant Maxwell's equations under coordinate transformations has opened up new possibilities to manipulate the electromagnetic fields. In this paper we report on applying the finite-embedded coordinate transformation method to design electromagnetic beam modulating devices both in the Cartesian coordinates and in the cylindrical coordinates. By designing the material constitutive tensors of the transformation optical structures through different kinds of coordinate transformations, either the beam width of an incident Gaussian plane wave could be modulated by a slab, or the wave propagating direction of an omni-directional source could be modulated through a cylindrical shell. We present the design procedures and the full wave electromagnetic simulations that clearly confirm the performance of the proposed beam modulating devices.