中国物理B ›› 2009, Vol. 18 ›› Issue (11): 4924-4931.doi: 10.1088/1674-1056/18/11/051

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Bloch oscillation and Landau\ben Zener tunnelling in a modulated optical lattice in a photovoltaic photorefractive crystal

张冰志, 崔虎, 李湘衡, 佘卫龙   

  1. State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China
  • 收稿日期:2009-03-02 修回日期:2009-04-21 出版日期:2009-11-20 发布日期:2009-11-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10874251).

Bloch oscillation and Landau--Zener tunnelling in a modulated optical lattice in a photovoltaic photorefractive crystal

Zhang Bing-Zhi(张冰志), Cui Hu(崔虎), Li Xiang-Heng(李湘衡), and She Wei-Long(佘卫龙)†   

  1. State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China
  • Received:2009-03-02 Revised:2009-04-21 Online:2009-11-20 Published:2009-11-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10874251).

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摘要： We theoretically study the beam dynamical behaviour in a modulated optical lattice with a quadratic potential in a photovoltaic photorefractive crystal. We find that two different Bloch oscillation patterns appear for the excitation of both broad and narrow light beams. One kind of optical Landau--Zener tunnelling also appears upon the Bloch oscillation and can be controlled by adjusting the parameter of the optical lattice. Unlike the case of linear potential, the energy radiation due to Landau--Zener tunnelling can be confined in modulated lattices of this kind. For high input intensity levels, the Landau--Zener tunnelling is suppressed by the photovoltaic photorefractive nonlinearity and a symmetry breaking of beam propagation from the modulational instability appears.

Abstract: We theoretically study the beam dynamical behaviour in a modulated optical lattice with a quadratic potential in a photovoltaic photorefractive crystal. We find that two different Bloch oscillation patterns appear for the excitation of both broad and narrow light beams. One kind of optical Landau--Zener tunnelling also appears upon the Bloch oscillation and can be controlled by adjusting the parameter of the optical lattice. Unlike the case of linear potential, the energy radiation due to Landau--Zener tunnelling can be confined in modulated lattices of this kind. For high input intensity levels, the Landau--Zener tunnelling is suppressed by the photovoltaic photorefractive nonlinearity and a symmetry breaking of beam propagation from the modulational instability appears.

Key words: Bloch oscillation, Landau--Zener tunnelling, double-period lattice, photovoltaic photorefractive

中图分类号:  (Other nonlinear optical materials; photorefractive and semiconductor materials)

  • 42.70.Nq
72.40.+w (Photoconduction and photovoltaic effects) 42.65.Hw (Phase conjugation; photorefractive and Kerr effects)