Metamaterials: Negative refractive index in ... - Theory.nipne.ro

Idealized hypotheses (<strong>in</strong>itially considered) and the real world1. The electric and the magnetic properties do not <strong>in</strong>teract to each other2. Absorption (losses) <strong>in</strong> the materials is negligible3. Simple geometrical structures, ignor<strong>in</strong>g anisotropy (1-D, 2-D)#1 Not valid careful design to match the negative bands for ε eff , μ eff .#2 and #3 also not valid much research effort necessary new"atomic structures" (geometries), new materials, new pr<strong>in</strong>ciples to getdesired effects (some us<strong>in</strong>g PhC <strong>in</strong>stead of NRI metamaterials).Absorption ε, μ, n - complex quantities: n = n' + jn"; ε = ε' + jε"; μ = μ' + jμ"Useful effects: n'; Losses: n"; Causality: ε" > 0; μ" > 0Factor of merit for negative <strong>refractive</strong> <strong><strong>in</strong>dex</strong>: F = – n'/n"Double-negative materials: n' < 0 because both, ε' < 0, μ' < 0 F largeS<strong>in</strong>gle-negative materials: n' < 0 only because ε' < 0, and μ' > 0 F smallASTiGMAT