摘要
基于矢量德拜理论,研究了双环角向偏振涡旋光束经大数值孔径透镜的聚焦,且在聚焦场中考虑存在两种不同介质。研究表明当涡旋光束的拓扑电荷数为1,且当透镜孔径半径与入射双环角向偏振涡旋光束的束腰半径之比为1.5时,聚焦光束可得到一个尺寸只有零点几个波长的局域空心光束。局域空心光斑的横向半径仅为0.38λ,而空心长度为2.37λ。此外还研究了透镜的数值孔径以及光束的入射拦截比对不同介质引起聚焦光束焦移的影响。
Based on vectorial Debye theory,the double-ring-shaped azimuthally polarized vortex beam focused by a high numerical aperture through a dielectric interface is investigated.The investigation indicated that when the topological charge of the incident vortex beam is unity and the ratio of the pupil radius to the incident beam radius is 1.5,a small bottle beam can be obtained.The radius of the bottle is,and the length is.Moreover,it is found that the mismatch of the refractive indices induce focal shift,which is dependent on the numerical aperture（NA） and the degree of truncation of the incident beam by a pupil.
出处
《三明学院学报》
2010年第6期553-557,共5页
Journal of Sanming University
关键词
角向偏振涡旋光束
大数值孔径
聚焦
局域空心光束
焦移
azimuthally polarized vortex beam
high-numerical aperture objective
focusing
bottle beam
focal shift
