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When a material is coupled with a metamaterial exhibiting opposite optical properties, they can annihilate. A portion of space is optically removed as a result, allowing light to propagate through the whole structure without diffraction. 1 Optical antimatter behavior is a generalization of the superlens effect, where metamaterial properties are exploited to overcome the diffraction limit. These extraordinary electromagnetic media are also expected to give rise to other interesting phenomena. In particular, an extremely directive beam appears when a divergent beam, or an internal point source, impinges on a medium with a refractive index close to zero.Metamaterials are artificial materials with structures specifically engineered to have optical properties that are not found in nature, such as a negative refractive index. We use thousands of coupled slabs of equal or almost equal thickness comprising air, which has a refractive index of 1, and metamaterial ‘anti-air’with an effective refractive index equal to–1. The average refractive index is zero: a quasi-zero (QZAI) medium. The total effect of such complementary media is light transmission in the plane without diffraction, preserving the input source profile. We have experimentally verified these theoretical predictions using a macroscopic sample with a length of 4mm. 2 In our sample the metamaterial antimatter slabs are composed of a photonic crystal (PhC) made from silicon (n D 3: 45 for incident light at wavelength D 1: 55m) with air holes arranged in a hexagonal lattice in the (x; z) plane. The holes have a radius r, lattice parameter a, and ratio r= a D 0: 38. This particular PhC shows an almost isotropic …
Publication date: 
1 Jan 2011
Biblio References: 
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