Browsing by Subject "Cylindrical cavities"

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    Observation of polarized gain from aligned colloidal nanorods
    (Royal Society of Chemistry, 2015) Gao, Y.; Ta, V. D.; Zhao, X.; Wang Y.; Chen R.; Mutlugün, E.; Fong, K. E.; Tan S.T.; Dang C.; Sun, X. W.; Sun, H.; Demir, Hilmi Volkan
    In recent years, colloidal semiconductor nanorods have attracted great interest for polarized spontaneous emission. However, their polarized gain has not been possible to achieve so far. In this work we show the highly polarized stimulated emission from the densely packed ensembles of core-seeded nanorods in a cylindrical cavity. Here CdSe/CdS dot-in-rods were coated and aligned on the inner wall of a capillary tube, providing optical feedback for the nanorod gain medium. Results show that the polarized gain originates intrinsically from the aligned nanorods and not from the cavity and that the optical anisotropy of the nanorod ensemble was amplified with the capillary tube, resulting in highly polarized whispering gallery mode lasing. The highly polarized emission and lasing, together with easy fabrication and flexible incorporation, make this microlaser a promising candidate for important color conversion and enrichment applications including liquid crystal display backlighting and laser lighting. This journal is © The Royal Society of Chemistry.
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    ItemOpen Access
    RCS study of cylindrical cavity-backed apertures with outer or inner material coating: the case of e-polarization
    (IEEE, 1993) Çolak, Dilek; Altıntaş, Ayhan; Nosich, A. I.
    Cavity-backed apertures (CBA) are encountered as parts of any airborne or spaceborne radar targets. Most familiar of them are, probably, air inlets and engine tubes, known to contribute a great deal to radar cross section (RCS) of jet aircraft. In the present study, the dual-series-based solution is obtained for the scattering of an E-polarized plane wave from the cavity-backed aperture which is formed by a slitted infinite circular cylinder coated with absorptive material. The material coating can be done on the inner or outer surface of the cylinder. For both cases, numerical results are presented for the RCS and comparisons of the suppression of RCS are given for two different realistic absorptive materials.