Browsing by Subject "Polarization independent"

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    Negative phase advance in polarization independent, multi-layer negative-index metamaterials
    (Optical Society of American (OSA), 2008) Aydın, Koray; Zhaofeng, Li; Şahin, Levent; Özbay, Ekmel
    We demonstrate a polarization independent negative-index metamaterial (NIM) at microwave frequencies. Transmission measurements and simulations predict a left-handed transmission band with negative permittivity and negative permeability. A negative-index is verified by using the retrieval procedure. Effective parameters of single-layer and twolayer NIMs are shown to be different. Negative phase advance is verified within the negative-index regime by measuring the phase shift between different sized negative-index metamaterials. Backward wave propagation is observed in the numerical simulations at frequencies where the phase advance is negative. ©2008 Optical Society of America.
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    Optically thin composite resonant absorber at the near-infrared band: A polarization independent and spectrally broadband configuration
    (Optical Society of American (OSA), 2011) Boratay Alici, K.; Burak Turhan, A.; Soukoulis, C.M.; Özbay, Ekmel
    We designed, fabricated, and experimentally characterized thin absorbers utilizing both electrical and magnetic impedance matching at the near-infrared regime. The absorbers consist of four main layers: a metal back plate, dielectric spacer, and two artificial layers. One of the artificial layers provides electrical resonance and the other one provides magnetic resonance yielding a polarization independent broadband perfect absorption. The structure response remains similar for the wide angle of incidence due to the sub-wavelength unit cell size of the constituting artificial layers. The design is useful for applications such as thermal photovoltaics, sensors, and camouflage. ©2011 Optical Society of America.
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    A planar metamaterial: Polarization independent fishnet structure
    (Elsevier BV, 2008) Alici, K. B.; Özbay, Ekmel
    We numerically and experimentally investigate a planar metamaterial that is composed of connected cut-wire pairs and continuous wires operating at 21 GHz. The characterization was performed by using the effective medium theory. The existence of negative refraction is concluded from the transmission data of four structures: cut-wire pairs, shorted cut-wire pairs, composite metamaterial, and shorted composite metamaterial.