A polarization-insensitive, square split-ring resonator（SSRR） is simulated and experimented. By investigating the influence of the asymmetrical arm width in typical SSRRs, we find that the variation of the arm width...A polarization-insensitive, square split-ring resonator（SSRR） is simulated and experimented. By investigating the influence of the asymmetrical arm width in typical SSRRs, we find that the variation of the arm width enables a blue shift of the resonance frequency for the 0° polarized wave and a red shift of the resonance frequency for the 90° polarized wave. Thus, the resonance frequency for the 0° polarized wave and the resonance frequency for the 90° polarized wave will be identical by asymmetrically adjusting the arm width of the SSRR. Two modified, split-ring resonators（MSRRs） that are insensitive to the polarization with asymmetrical arm widths are designed, fabricated, and tested. Excellent agreement between the simulations and experiments for the MSRRs demonstrates the polarization insensitivity with asymmetrical arm widths. This work opens new opportunities for the investigation of polarization-insensitive, split-ring resonator metamaterials and will broaden the applications of split-ring resonators in various terahertz devices.展开更多
SiAlON phosphors doped with rare earths have attracted much attention on the application of light emitting diode（LEDs） benefitting from their outstanding thermal stability, chemical stability and broad emission band...SiAlON phosphors doped with rare earths have attracted much attention on the application of light emitting diode（LEDs） benefitting from their outstanding thermal stability, chemical stability and broad emission band properties. In this work, Eu-doped β-SiAlON green phosphors with composition Si（5.5）Al（0.5）O（0.5）N（7.5）：0.035Eu^2＋ were prepared by a highly efficient combustion synthesis（CS） method. The effect of comburent ratios（i.e., Si ＆ Al） were systematically investigated by adjusting the starting compositions of reactants. It was confirmed that the ratios of Si and Al reactants had an intense influence on the phase composition, microstructure and photoluminescence properties of as-synthesized phosphors by directly determining the systematic energy in CS. The as-prepared β-SiAlON：Eu^2＋ phosphors featured with high phase purity, uniform particle size of 3–5 μm, well-crystalline morphology and outstanding luminescent properties of green emission under UV or blue excitation were synthesized with 67.5 wt.% ratio of Si and no Al comburent.展开更多
基金supported by the National High Technology Research and Development Program of China (No. 2011AA010204)the National Natural Science Foundation of China (Nos. 91438118 and 61370011)the Fundamental Research Funds for the Central Universities of China (No. ZYGX2014J037)
文摘A polarization-insensitive, square split-ring resonator（SSRR） is simulated and experimented. By investigating the influence of the asymmetrical arm width in typical SSRRs, we find that the variation of the arm width enables a blue shift of the resonance frequency for the 0° polarized wave and a red shift of the resonance frequency for the 90° polarized wave. Thus, the resonance frequency for the 0° polarized wave and the resonance frequency for the 90° polarized wave will be identical by asymmetrically adjusting the arm width of the SSRR. Two modified, split-ring resonators（MSRRs） that are insensitive to the polarization with asymmetrical arm widths are designed, fabricated, and tested. Excellent agreement between the simulations and experiments for the MSRRs demonstrates the polarization insensitivity with asymmetrical arm widths. This work opens new opportunities for the investigation of polarization-insensitive, split-ring resonator metamaterials and will broaden the applications of split-ring resonators in various terahertz devices.
基金Project supported by the National High Technology Research and Development Program of China(2015AA034601)
文摘SiAlON phosphors doped with rare earths have attracted much attention on the application of light emitting diode（LEDs） benefitting from their outstanding thermal stability, chemical stability and broad emission band properties. In this work, Eu-doped β-SiAlON green phosphors with composition Si（5.5）Al（0.5）O（0.5）N（7.5）：0.035Eu^2＋ were prepared by a highly efficient combustion synthesis（CS） method. The effect of comburent ratios（i.e., Si ＆ Al） were systematically investigated by adjusting the starting compositions of reactants. It was confirmed that the ratios of Si and Al reactants had an intense influence on the phase composition, microstructure and photoluminescence properties of as-synthesized phosphors by directly determining the systematic energy in CS. The as-prepared β-SiAlON：Eu^2＋ phosphors featured with high phase purity, uniform particle size of 3–5 μm, well-crystalline morphology and outstanding luminescent properties of green emission under UV or blue excitation were synthesized with 67.5 wt.% ratio of Si and no Al comburent.
