Metamaterials for optical and radio communications

Abstract

We present here two examples of metamaterials for applications in the telecoms domain. The first concerns the realization of an ultra compact directive electronically reconfigurable antenna. The second deals with an infrared left-handed metamaterial working under normal incidence. For the first application, we use a composite phase varying metamaterial. An adjustable resonance radiating frequency between 7.9 and 8.2 GHz is obtained and a drastic enhancement in the directivity of the antenna is observed for a cavity thickness as small as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>λ</mml:mi> <mml:mo stretchy="false">/</mml:mo> <mml:mn>75</mml:mn> </mml:math> (0.5 mm!). Concerning the second application we present simulations and measurements of a metamaterial made of gold wires and C-shaped nanostructures on silicon at infrared wavelengths. Both plasmonic resonances occur at 1.7 and 4.2 μm, corresponding to a simultaneously negative permittivity and permeability. A simplified version of this metamaterial is realized in the microwave domain. This new metamaterial is characterized and the left-handed behavior is experimentally demonstrated.