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

作     者：张冰志 崔虎 李湘衡 佘卫龙 

作者机构：State Key Laboratory of Optoelectronic Materials and TechnologiesSun Yat-Sen University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2009年第18卷第11期

页      面：4924-4931页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 0702[理学-物理学] 

基　　金：Project supported by the National Natural Science Foundation of China (Grant No 10874251) 

主　　题：Bloch oscillation Landau-Zener tunnelling double-period lattice photovoltaic photore- fractive 

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.