Zhang Yuqiu, Hou Tianyue, Chang Hongxiang, Yu Tao, Chang Qi, Jiang Man, Ma Pengfei, Su Rongtao, Zhou Pu
Opt Express. 2021 Feb 15;29(4):5259-5269. doi: 10.1364/OE.417038.
We investigate the focusing properties of cylindrical vector beams (CVBs) generated from the combination of an array of beams, each with sub-apertures and controllable polarization. The analytical expression of the tight focusing field of the combined CVBs has been derived based on the Richard-Wolf vector diffraction integral. To obtain a desired focal spot size which includes efficient sidelobe suppression, the required parameters, such as the exit sub-aperture, numerical aperture and truncation parameter, have been studied in detail. The result shows that the combined CVB distribution has a good match with the theoretical ideal CVB distribution. However, compared with the ideal CVBs, the focal spot width produced by the combined radially polarized beams is smaller. With the increase of initial polarization rotation of sub-aperture, the focal spot width increases, and the focal shape shifts from Gaussian-like to a flat-topped distribution and then to an annular distribution. Furthermore, flexible focal field tailoring can also be realized by adjusting the initial polarization rotation of each sub-aperture. These results might provide a valuable reference for material processing, microlithography and multi-particle manipulation.
我们研究了由一系列光束组合产生的圆柱矢量光束（CVB）的聚焦特性，这些光束中的每一束都具有子孔径且偏振可控。基于理查德 - 沃尔夫矢量衍射积分，推导了组合CVB紧密聚焦场的解析表达式。为了获得所需的焦斑尺寸，包括有效的旁瓣抑制，已详细研究了所需参数，如出射子孔径、数值孔径和截断参数。结果表明，组合CVB分布与理论理想CVB分布具有良好的匹配。然而，与理想CVB相比，组合径向偏振光束产生的焦斑宽度更小。随着子孔径初始偏振旋转角度的增加，焦斑宽度增大，焦斑形状从类高斯分布转变为平顶分布，然后再转变为环形分布。此外，通过调整每个子孔径的初始偏振旋转角度，还可以实现灵活的焦场剪裁。这些结果可能为材料加工、微光刻和多粒子操纵提供有价值的参考。
