Metamaterials
Critique and Alternatives
Chapter One
Why Periodic Structures Cannot
Synthesize Negative Indices
of Refraction
1.1 INTRODUCTION
1.1.1 Overview
In this chapter we first list some of the features that are widely accepted
as being facts regarding metamaterials with simultaneously negative µ
and [epsilon]:
1. The index of refraction is negative.
2. The phase of a signal advances as it moves away from the source.
3. The evanescent waves increase as they get farther away from the
source.
4. Whereas the E- and H-fields in an ordinary material form a right-handed
triplet with the direction of phase propagation, in a material
with negative µ and [epsilon], they form a left-handed triplet.
Such materials have never been found in nature. However, numerous
researchers have suggested ways to produce them artificially. Periodic
structures of elements varying from simple straight wires to very elaborate
concoctions have been claimed to produce a negative index of refraction.
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