Browsing by Subject "Metallicity gap"

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Open Access
Experimental investigation of layer-by-layer metallic photonic crystals
(Institution of Electrical Engineers, 1998-12) Temelkuran, B.; Altug, H.; Özbay, Ekmel
The authors have investigated the transmission properties and defect characteristics of layer-by-layer metallic photonic crystals. They have demonstrated experimentally that the metallicity gap of these crystals extends to an upper band-edge frequency, and no lower edge was detected down to 2 GHz. The defect structures built around these crystals exhibited high transmission peak amplitudes (100%) and high Q factors (2250). The crystals with low filling ratios (around 1-2%) were tested and were still found to possess metallic photonic crystal properties. These crystals exhibited high reflection rates within the metallicity gap and reasonable defect mode characteristics. A power enhancement factor of 190 was measured for the electromagnetic (EM) wave within planar cavity structures, by placing a monopole antenna inside the defect volume. These measurements show that detectors embedded inside a metallic photonic crystal can be used as frequency selective resonant cavity enhanced (RCE) detectors with increased sensitivity and efficiency when compared to conventional detectors.
Open Access
Highly doped silicon micromachined photonic crystals
(IEEE, Piscataway, NJ, United States, 2000) Temelkuran, B.; Bayındır, Mehmet; Özbay, Ekmel; Kavanaugh, J. P.; Sigalas, M. M.; Tuttle, G.
Summary form only given. Photonic crystals are periodic structures with the property of reflecting the electromagnetic (EM) waves in all directions within a certain frequency range. These structures can be used to control and manipulate the behaviour of EM waves. Although earlier work concentrated on building these crystals with dielectric materials, there are certain advantages of introducing metals to photonic crystals. First, metals offer a high rejection rate when compared to the dielectric crystals. Second, for microwave applications, the dimensions of metallic crystals can be kept much smaller than the minimum dimensions needed for a typical dielectric crystal. In the paper, we propose a method for the fabrication of layer-by-layer metallic photonic crystals. A similar method had been used by Ozbay et al. to fabricate dielectric photonic crystals using silicon wafers. We fabricated a new layer-by-layer photonic crystal using highly doped silicon wafers.