Yu-Hai Wang

Jilin Normal University, Yung-chi, Jilin Sheng, China

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Publications (7)7.68 Total impact

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    ABSTRACT: A series of heteroleptic cyclometalated Ir (III) complexes for OLEDs application have been investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, electronic structures, and the lowest-lying singlet absorptions and triplet emissions of (piq)2Ir(acac) (labeled 1) and theoretically designed models (piq)2Ir(dpis) (labeled 2), (4Fpiq)2Ir(dpis) (labeled 3), (4F5M-piq)2Ir(dpis) (labeled 4), (4,5-2F-piq)2Ir(dpis) (labeled 5) and (5-F-piq)2Ir(dpis) (labeled 6) were investigated with density functional theory (DFT)-based approaches, where, piq=1-phenylisoquinolato, acac=acetylacetonate and dpis=diphenylimidodisilicate. Their structures in the ground and excited states have been optimized at the DFT/B3LYP/LANL2DZ and TDDFT/B3LYP/LANL2DZ levels, and the lowest absorptions and emissions were evaluated at B3LYP and M062X level of theory, respectively. Furthermore, the energy-transfer mechanism of these complexes also be analyzed here, and the result shown that the complexes 1-6 are having the low efficiency roll-off property. Except that, the oscillator strength analyze shown that the complexes 2-6, which were designed by theory, are suitable for OLED since their high oscillator strength property.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 06/2014; 134C:406-412. · 1.98 Impact Factor
  • Optik - International Journal for Light and Electron Optics 11/2013; 124(22):5520-5523. · 0.77 Impact Factor
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    ABSTRACT: Formulas of the transfer functions and the output power gains are presented, amplifying characteristics are analyzed, and simulation is performed for an Er3+–Yb3+-co-doped microring resonator. Under the pump wavelength of 980 nm and the central signal wavelength of 1550 nm, the dependence of the output power gain on the amplitude coupling ratio, pump power, signal power, and the dopant concentration is investigated, the output spectra are presented, and the optimization of the device is carried out. Simulated results show that the output power gain of this device is much larger than that of the Er3+–Yb3+-co-doped straight waveguide amplifier (EYCDWA) with the same waveguide parameters.
    Optics & Laser Technology 01/2010; · 1.37 Impact Factor
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    ABSTRACT: In terms of the coupled mode theory, formulas of the transfer function and the output power gain are presented for an Er/Yb co-doped parallel-cascaded double microring resonator. Around the pump wavelength of 0.98 μm and the central signal wavelength of 1.55 μm, analysis is performed for the dependence of the output power gain on the pump power, signal power, dopant concentration, amplitude coupling ratio, and ring spacing. The results show that the output power gain of this device is much larger than that of the Er/Yb co-doped waveguide amplifier with identical waveguide lengths. In the case of the amplitude coupling ratio κ = 0.064, ring spacing L2 = 10π R, pump power Pp0 = 8 mW, signal power Ps0 = 37.2 μW, Er ion concentration NEr = 1 × 26 m, and Yb ion concentration NYb = 3 × 27 m, the device can produce higher signal power gain from 11.9 dB even up to 70 dB.
    Fiber and Integrated Optics 09/2009; 28(5):343-353. · 0.28 Impact Factor
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    ABSTRACT: In order to analyze the power conversion efficiency (PCE) and the gain characteristics of the phosphate glass Er3+–Yb3+-co-doped waveguide amplifier (EYCDWA), formulas are derived from the rate equations and the light propagation equations under the uniform dopant and the steady-state conditions. In the derivation of these formulas, we have neglected the amplified spontaneous emission (ASE) and have introduced the initial energy transfer efficiency. By using these formulas, the effects of the pump power, signal power and waveguide length on the PCE and the gain characteristics of the EYCDWA are analyzed, and some useful results are obtained in three kinds of pumped styles, i.e. the forward-, backward- and bidirectional pumped styles.
    Optics & Laser Technology 01/2009; 41(5):545-549. · 1.37 Impact Factor
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    ABSTRACT: By employing perturbation theory, a technique called the 'equivalent rectangular waveguide method' is proposed for analyzing the transmission characteristics of polymeric arrayed waveguide grating (AWG) multiplexers with non-ideal core cross sections, which are modeled by the 'tanh' function. Simulation results show that the non-ideal core cross sections cause the shift of the transmission spectrum, and result in the increase of crosstalk compared with the device originally designed with exact rectangular core cross sections. In order to eliminate the shift of the transmission spectrum, reduce the crosstalk and further realize accurate demultiplexing, the redesign of the AWG device is carried out.
    Journal of Optics A Pure and Applied Optics 09/2007; 9(10):884. · 1.92 Impact Factor
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    ABSTRACT: Novel formulas for analyzing the gain characteristics of the phosphate glass erbium-ytterbium (Er3+-Yb3+) co-doped waveguide amplifier (EYCDWA) are derived from the rate equations and the light propagation equations under the uniform dopant and steady-state conditions. In the derivation of these formulas, we have neglected the amplified spontaneous emission (ASE) and have introduced the initial energy transfer efficiency. By using these formulas, the effects of the pump power, signal power, dopant concentration and waveguide length on the gain characteristics of the EYCDWA are analyzed, the comparison is performed between the EYCDWA and the singly erbium-doped waveguide amplifier (EDWA), and some useful results are obtained.

Publication Stats

7.68 Total Impact Points

Institutions

  • 2014
    • Jilin Normal University
      Yung-chi, Jilin Sheng, China
  • 2007–2010
    • Jilin University
      • • College of Electronic Science and Engineering
      • • State Key Laboratory on Integrated Optoelectronics
      Changchun, Jilin Sheng, China