基于矢量德拜理论，研究了贝塞尔-高斯径向偏振光束经过衍射光学元件(DOE)和高数值孔径(NA)透镜组成的光学系统后经介质分界面的强聚焦特性。设计DOE 的参数对入射的贝塞尔-高斯径向偏振光束进行调制，在聚焦场中能得到沿光轴方向的三维多点光俘获结构-光链。研究结果表明，入射光束的拦截比(即透镜孔径半径与入射光束束腰半径比)、数值孔径和聚焦场介质折射率都会影响光束的强聚焦特性。当光束的拦截比增大到一个值时，聚焦场的光链会转变成暗通道，并且在不改变暗通道宽度的情况下，暗通道的长度会随着介质折射率的增大而增长。

Based on the vectorial Debye theory, the tightly focusing properties of Bessel-Gaussian radially polarized beam through a high numerical aperture (NA) with a diffractive optical elements (DOE) and a dielectric interface are investigated. A three-dimensional optical chain along optical axis can be obtained by designing the DOE to spatially modulate the incoming Bessel-Gaussian radially polarized beam. Research results show that the focusing shape in the focal area can be controlled by changing the interception ratio of the aperture radius to the incident beam waist radius, numerical aperture and the refractive index of the medium in the focal region. When the interception ratio is beyond to a constant value, a focal dark channel can be obtained. The length of the focal dark channel increases with the increasing of refractive index of the medium in the focal region in case of not changing the width of the focal dark channel.