Browsing by Subject "Horn antennas"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Open Access Experimental demonstration of highly confined photonic crystal based waveguides(IEEE, 2001) Bayındır, Mehmet; Özbay, Ekmel; Temelkuran, B.; Sigalas, M. M.; Soukoulis, C. M.; Biswas, R.; Ho, K. M.The bending and guiding of the electromagnetic (EM) waves in highly confined waveguides was demonstrated. The electromagnetic waves were constructed by removing a single rod from a perfect three layer-by-layer photonic crystals. A layer-by-layer dielectric photonic crystal based on square shaped alumina rods was used with center-to-center separation of 1.12 cm. The results suggested the use of the layer-by-layer photonic crystal structure in the design of optoelectronic integrated circuits.Item Open Access Guiding and bending of photons via hopping in three-dimensional photonic crystals(IEEE, Piscataway, NJ, United States, 2000) Bayındır, Mehmet; Temelkuran, B.; Özbay, EkmelFor the past decade, photonic crystals, also known as photonic bandgap (PBG) materials, have inspired great interest because of their novel scientific and engineering applications such as the inhibition of spontaneous emission, thresholdless lasers, optical circuits, antennas, waveguides, detectors, fibers, and so on. Creating defect states within the PBG are very important for such applications. Recently, we have reported the eigenmode splitting due to coupling of the localized defects and guiding of the electromagnetic (EM) waves through a periodic arrangement of such defects in three-dimensional (3D) photonic crystals. Although the modes of each cavity were tightly confined at the defect sites, overlapping between the nearest-neighbor modes is enough to provide the propagation of photons via hopping. We report on the observation of guiding and bending of EM wave through evanescent defect modes for three different PBG waveguide structures.Item Open Access Microwave transmission through metamaterials in free space(2002) Aydın, Koray; Bayındır, Mehmet; Özbay, EkmelTo investigate properties of metamaterials, composite structures which consists of periodical arrangement of thin copper wires and SRRs on a circuit board was constructed. Through this, the transmission properties of composite metamaterials at microwave frequencies were investigated. It was observed that a pass-band was formed within the forbidden transmission bands of thin wire and SRR structures.Item Open Access Photonic band gap structures for WDM applications(IEEE, 2002) Bayındır, Mehmet; Akarca, S. S.; Özbay, EkmelA new structure by combining a single cavity and coupled-cavity waveguides (CCWs) for wavelength division multiplexing (WDM) applications was proposed. As such, a structure in which the coupling between the cavity mode and the guiding model allows to drop a selective wavelength λi was designed. The selectivity of dropping wavelength was determined by local properties of the cavity modes. Such results were said to be important for designing future ultrasmall optical circuits.