基于圆偏振涡旋光束强聚焦的平顶光束的构成  

Flattop Beam Creation Based on Strong Focusing of Circularly Polarized Vortex Beams

作　　者：刘键[1] 杨艳芳[1] 何英[1] 刘国威[1] 郑晓[1] 

机构地区：[1]上海大学理学院物理系,上海200444

出　　处：《光学学报》2014年第5期235-242,共8页Acta Optica Sinica

基　　金：国家自然科学基金(61108010;11204170);上海市自然科学基金(11ZR1412300)

摘　　要：由于圆偏振涡旋光束可以表征为柱坐标的径向矢量光束和角向矢量光束的线性叠加,因而在研究其聚焦特性时,必须考虑具有拓扑核的径向矢量光束聚焦后有角向分量和角向矢量光束聚焦后有径向分量。在修正关于圆偏振涡旋光束强聚焦公式的基础上,重新模拟计算了不同拓扑核的圆偏振涡旋光束的强聚焦特性。结果显示不仅单自旋手性的圆偏振涡旋光束聚焦能形成平顶光束,而且两束不同的自旋手性的涡旋光束的叠加聚焦也可以实现平顶光束。通过调节光束的振幅、束腰半径以及遮挡通光孔径可以有效地改变平顶光束的半宽。Because circularly polarized vortex beam can be characterized as the linear super position of radiallypolarized and azimuthally polarized components in the cylindrical coordinate, when study the focusing properties ofthe circularly polarized vortex beam, we must consider radially polarized vector beam with topological nuclei hasazimuthal component after focusing and azimuthally polarized vector beam has radial component after focusing. Basedon the corrected tightly focusing formula of the circularly polarized vortex beam, we afresh study the tightly focusingproperties of the circularly polarized vortex beams with different topological nuclei. The results show that not onlythe focusing of the single handedness of the circularly polarized vortex beam but also the focusing of superposition oftwo circularly polarized vortex beams can generate flattop beam. By choosing the proper amplitude ratio, waist radiusand the aperture blocking, the half-width of flattop beam can be changed effectively.

关 键 词：物理光学 偏振 涡旋光束 平顶光束 

分 类 号：O436[机械工程—光学工程]