Yong Zhang

Publications (3)10.77 Total impact

• Article: Diffraction Interference Induced Superfocusing in Nonlinear Talbot Effect

  Dongmei Liu, Yong Zhang, Jianming Wen, Zhenhua Chen, Dunzhao Wei, Xiaopeng Hu, Gang Zhao, S. N. Zhu, Min Xiao
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  ABSTRACT: We report a simple, novel sub-diffraction method, i.e. diffraction interference induced super-focusing in second-harmonic (SH) Talbot effect, to achieve focusing size of less than {\lambda}_pump/8 without involving evanescent waves or sub-wavelength apertures. By tailoring point spread functions with Fresnel diffraction interference, we observe periodic SH sub-diffracted spots over a hundred of micrometers away from the sample. Our demonstration is the first experimental realization of the proposal by Toraldo Di Francia pioneered 60 years ago for super-resolution imaging.
  04/2013;
• Source

  Available from: Jianming Wen

  Article: Fractional second-harmonic Talbot effect.

  Zhenhua Chen, Dongmei Liu, Yong Zhang, Jianming Wen, S N Zhu, Min Xiao
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  ABSTRACT: We demonstrate the fractional second-harmonic (SH) Talbot effect in a hexagonally poled LiTaO3 crystal. We carefully record the SH Talbot images at 1/2, 1/3, and 1/4 Talbot lengths, which are well matched with the simulated images by using the modified Rayleigh-Sommerfeld diffraction formula. A simplified model with a hexagonal array is adopted in the simulations. Also, we use a modified reciprocal vector theory to analytically explain the evolution of the SH array at fractional Talbot lengths. Our results show that the images are sensitive to the duty circle and the background of the array.
  Optics Letters 02/2012; 37(4):689-91. · 3.40 Impact Factor
• Article: Nonlinear Talbot effect.

  Yong Zhang, Jianming Wen, S N Zhu, Min Xiao
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  ABSTRACT: We propose and experimentally demonstrate the nonlinear Talbot effect from nonlinear photonic crystals. The nonlinear Talbot effect results from self-imaging of the generated periodic intensity pattern at the output surface of the crystal. To illustrate the effect, we experimentally observed second-harmonic Talbot self-imaging from 1D and 2D periodically poled LiTaO(3) crystals. Both integer and fractional nonlinear Talbot effects were investigated. The observation not only conceptually extends the conventional Talbot effect, but also opens the door for a variety of new applications in imaging technologies.
  Physical Review Letters 05/2010; 104(18):183901. · 7.37 Impact Factor