Zeng Yongxi, Chen Jian, Teng Houan, Mo Dewei, Wu Pinghui, Chen Musheng, Yu Yanzhong, Zhan Qiwen
Opt Express. 2023 Oct 9;31(21):34503-34513. doi: 10.1364/OE.501003.
We report an approach to simultaneously control orbital angular momentum (OAM) orientation and topological charge in highly localized optical vortices by employing a 4π focusing system. The required continuous wave illumination field in the pupil planes is derived by superimposing the radiation pattern of only one dipole placed at the focal point of the high numerical aperture lens and the corresponding tailored spiral phase factor. The topological charge and OAM orientation of the obtained focused fields are quantitatively evaluated based on the focal field distributions calculated by the Richards-Wolf vector diffraction integration theory. Results show that the OAM of the generated optical vortices can be tailored by changing the oscillation orientation of the mimic dipole and the topological charge of the superimposed spiral phase term. The presented method may find potential applications in optical trapping, optical tweezers, light-matter interaction, etc.
我们报告了一种通过采用4π聚焦系统来同时控制高度局域化光学涡旋中轨道角动量（OAM）取向和拓扑电荷的方法。通过叠加仅放置在高数值孔径透镜焦点处的一个偶极子的辐射模式和相应的定制螺旋相位因子，得出光瞳平面中所需的连续波照明场。基于由理查兹 - 沃尔夫矢量衍射积分理论计算出的焦场分布，对所获得的聚焦场的拓扑电荷和OAM取向进行了定量评估。结果表明，通过改变模拟偶极子的振荡取向和叠加螺旋相位项的拓扑电荷，可以定制所产生光学涡旋的OAM。所提出的方法可能在光学捕获、光镊、光与物质相互作用等方面找到潜在应用。
