Xue-liang Kang

Publications (3)10.57 Total impact

• Article: Design of DOE for generating a needle of a strong longitudinally polarized field.

  Kun Huang, Peng Shi, Xue-liang Kang, Xiaobo Zhang, Yong-ping Li
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  ABSTRACT: A needle of strong longitudinally polarized field with homogeneous intensity along the optical axis, long depth of focus, and subdiffraction beam size can be generated by focusing a radially polarized light with a high-NA lens and a diffractive optical element (DOE) with belts. A method combining the global-search-optimization algorithm and the tight focusing properties of the radially polarized light is proposed to design the DOE. Based on the tight focusing properties, the light incident on the lens is divided into two parts: areas A and B. We discover that the longitudinal field in the focal region is mainly dependent on the number of belts in area B but not the total number of belts in the DOE.
  Optics Letters 04/2010; 35(7):965-7. · 3.40 Impact Factor
• Article: Creation of large band gap with anisotropic annular photonic crystal slab structure.

  Peng Shi, Kun Huang, Xue-liang Kang, Yong-ping Li
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  ABSTRACT: A two-dimensional anisotropic annular photonic crystal slab structure composed of circular air holes and dielectric rods with finite thickness in a triangular lattice is presented to achieve an absolute photonic band gap. Positive uniaxial crystal Tellurium is introduced to the structure with the extraordinary axis parallel to the extension direction of rods. The role of each geometric parameter is investigated by employing the conjugate-gradient method. A large mid-gap ratio is realized by the parameter optimization. A flat band called as anomalous group velocity within two large gaps is discovered and can be widely applied in many fields. A hybrid structure with GaAs slab and Te rods is designed to achieve a large gap and demonstrates that the annular structure can improve the gap effectively.
  Optics Express 03/2010; 18(5):5221-8. · 3.59 Impact Factor
• Article: Spectrum control by anisotropy in a cylindrical microcavity.

  Xue-Liang Kang, Yong-Ping Li, Shan-Liang Qiu, Jia-Xing Cai
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  ABSTRACT: Spectrum control by anisotropy in a cylindrical microcavity made of electric anisotropic medium was studied. A finite-difference time domain method for electric anisotropic medium and Volume-average Effective Permittivity approximation are applied to calculate the resonant frequencies and quality factors of Whispering-gallery modes. The resonant frequency for different whispering-gallery modes has a similar shift in direct proportion to the relative difference of two principal refractive indices. The quality factors decay exponentially due to directional emission when the difference of two principal refractive indices increases. This novel tuning characteristic of anisotropic cylindrical microcavity will play an important role in many areas, such as light source with tunable wavelength, tunable filter and sensor.
  Optics Express 12/2009; 17(26):23843-50. · 3.59 Impact Factor