Inverse Transformation Optics and Reflection Analysis for Two-Dimensional Finite Embedded Coordinate Transformation

TL;DR

This paper introduces inverse transformation optics to analyze boundary reflections in 2D finite embedded coordinate transformation media, providing a method to compute reflections and identify conditions for reflectionless boundaries.

Contribution

It develops a novel inverse transformation optics approach for reflection analysis in discontinuous 2D transformation media, enhancing understanding of boundary behaviors.

Findings

Reflection at the boundary can be analyzed via virtual space transformations.

A reflectionless boundary condition is derived.

Numerical verification confirms the theoretical approach.

Abstract

Inverse transformation optics is introduced, and used to calculate the reflection at the boundary of a transformation medium under consideration. The transformation medium for a practical device is obtained from a two-dimensional (2D) finite embedded coordinate transformation (FECT) which is discontinuous at the boundary. For an electromagnetic excitation of particular polarization, many pairs of original medium (in a virtual space V') and inverse transformation can give exactly the same anisotropic medium through the conventional procedure of transformation optics. Non-uniqueness of these pairs is then exploited for the analysis and calculation of the boundary reflection. The reflection at the boundary of the anisotropic FECT medium (associated with the corresponding vacuum virtual space V) is converted to the simple reflection between two isotropic media in virtual space V' by a selected inverse transformation continuous at the boundary. A reflectionless condition for the boundary of the FECT medium is found as a special case. The theory is verified numerically with the finite element method.