光涡旋偶极子经半屏衍射后的演化  

Evolution of an optical vortex dipole diffracted by a half screen

作　　者：高曾辉[1] 何德[1,2] 吕百达[2] 

机构地区：[1]宜宾学院计算物理重点实验室,宜宾644000 [2]四川大学激光物理与化学研究所,成都610064

出　　处：《物理学报》2011年第7期319-324,共6页Acta Physica Sinica

基　　金：国家自然科学基金(10874125)资助的课题~~

摘　　要：推导出寄居于高斯光束中的光涡旋偶极子经过半屏衍射后的解析传输公式.利用所得公式对光涡旋偶极子经半屏衍射后的演化做了详细研究.结果表明,与自由空间中光涡旋偶极子演化相比较,衍射场中会出现多对光涡旋偶极子,湮没方式与离轴量有关.随离轴参数的变化,偶极子出现不同的演化特性,但在演化过程中,拓扑电荷守恒.The analytical expression for the propagation of an optical vortex dipole （OVD） nested in a Gaussian beam diffracted by a half screen is derived and used to study the evolution of the diffracted OVD. It is shown that Compared with the case of the OVD evolution in free space, multi-pairs of the OVD may take place in the diffracted field, and the annihilation fashion depends on the off-axis displacement. A variety of the evolution behaviors of OVDs appear by varying the off-axis parameter, but the topological charge is conserved in the evolution process.

关 键 词：光涡旋偶极子 半屏衍射 拓扑电荷 

分 类 号：O463[机械工程—光学工程]