涡旋相位编码的径向矢量光束的紧聚焦特性

Compact focusing properties of radial vector beam with vortex phase encoding

为了研究涡旋相位编码的径向矢量高斯光束经过高数值孔径物镜之后的聚焦特性,采用RICHARDS和WOLF提出的矢量积分理论和数值模拟方法,对聚焦场的特征进行了理论分析和模拟实验验证,取得聚焦场分布随涡旋相位物理参量之间的数据关系。结果表明,当单个涡旋相位编码于径向矢量高斯光束时,在聚焦场能够获得2维的径向和纵向分量;当双涡旋相位对称地编码于径向高斯矢量光束时,聚焦场会出现两个光学暗点,此光学暗点处的折射率低于周围环境的折射率。这一结果对提高光学微操控的灵活性,以及对双微粒的捕获与操控是有帮助的。

In order to study the focusing properties of radial vector Gaussian beam with vortex phase encoding through objective mirror with high numerical aperture,the vector integral theory and numerical simulation method proposed by RICHARDS and WOLF were adopted.After theoretical analysis and simulation verification of the characteristics of focused field,the relationship between focused field distribution and vortex phase physical parameters was gotten.The results show that,when radial vector Gaussian beam is encoded by single vortex,2-D radial and longitudinal components of focused field can be obtained.When radial vector Gaussian beam is encoded by double vortex phase symmetrically,two optical dark cores are formed in focal plane.The refractive indexs of two optical dark cores are lower than the indexs of the surrounding environment.The study is helpful to improve the flexibility of optical micro-manipulation and capture and control the double minute.