高偏振级次轴对称偏振光束的聚焦特性
摘要
We study the high numerical aperture focusing properties and typical applications of axially-symmetric polarized beams (ASPBs) with high polarization orders. We calculate the field distribution near focus of an aplanatic system for incident ASPBs with different polarization orders and initial azimuthal angles, and based on the simulation results, we find some unique focusing properties of the beams, such as ever on-axis energy null, strong longitudinal field, and flowerlike intensity distribution at focus. In addition, we can manipulate the three-dimensional (3D) focused field distribution flexibly by use of diffractive optical elements (DOEs), which will give rise to some interesting applications, and we also discuss possible applications and present an example of a 3D optical chain at last.