圆形螺旋相位板的平面波夫琅和费衍射特性  

Properties of the Fraunhofer diffraction of a plane wave by a circular spiral phase plate

作　　者：李志焕[1] 吴福全[1] 陈君[2] 崔祥霞[2] 朱久凯[1] 

机构地区：[1]曲阜师范大学激光研究所,山东曲阜273165 [2]泰山学院物理与电子工程学院,山东泰安271021

出　　处：《光电子．激光》2013年第7期1439-1444,共6页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61107012);山东省自然科学基金(ZR2011FQ023);泰安市科技发展计划(20112005)资助项目

摘　　要：为了研究圆形螺旋相位板(SPP)对平面波的夫琅和费衍射特性,基于标量衍射理论给出了圆形SPP对有限孔径平面波进行夫琅和费衍射时所产生涡旋光束的光强表达式。理论模拟分析了圆形SPP的拓扑荷数n、半径R等参数对涡旋光束光强分布的影响,结果表明,当圆形SPP半径R不变时,随着拓扑荷n的增大,涡旋光束半径逐渐增大,并且光强分布中旁瓣的比重显著增强;当拓扑荷n不变时,圆形SPP的半径R增大,产生的涡旋光束半径反而会变小,但涡旋光束的相对形状基本保持不变。基于纯相位空间光调制器(SLM)实现了圆形SPP对有限孔径平面波的夫琅和费衍射,并对理论结果进行了实验验证,实验结果与理论分析一致。For studying the Fraunhofer diffraction properties of a plane and finite-radius wave by a circular spiral phase plate （SPP）, the analytical expression to describe the light intensity of the vortex beam pro- duced by the Fraunhofer diffraction based on the scalar diffraction theory is given. The effects of different parameters on the intensity distribution properties of the vortex beam, such as the topological charge n, the radius R of the circular SPP, are analyzed through theoretical modeling. Theoretical results show that when the radius R of the circular SPP is constant, the radius of the vortex beam would increase with the increasing topological charge n, and the proportion of the sidelobes is also enhanced significantly. Howev- er,when the topological charge n is constant,the radius of the vortex beam would decrease with the in- creasing radius of the circular SPP, and the shape of the vortex beam would remain basically unchanged. The Fraunhofer diffraction of a plane and finite-radius wave by a circular SPP is achieved with a phase- only spatial light modulator （SLM）, and experimental verifications about the above theoretical results are implemented. The experimental results and theoretical analvsis are in good agreement.

关 键 词：圆形螺旋相位板(SPP) 涡旋光束 夫琅和费衍射 纯相位空间光调制器(SLM) 叉形光栅 

分 类 号：O436.1[机械工程—光学工程]