Jiang Yunfeng, Zhao Shuofeng, Yu Wenlei, Zhu Xiuwei
J Opt Soc Am A Opt Image Sci Vis. 2018 Jun 1;35(6):890-894. doi: 10.1364/JOSAA.35.000890.
Controlling the trajectory of circular Airy beams (CABs) by negative launch angles would greatly reduce their abruptly autofocusing property. By numerically simulating the propagation of a circular Airy vortex beam with different initial launch angles, we demonstrate in this paper that a larger topological charge of optical vortex (OV) is quite helpful to enhance the abruptly autofocusing property under different launch angles (especially for negative launch angles), without affecting the focal position and trajectory. Two opposite OVs would attract each other and partially overlap in the focal plane of CAB under different launch angles, causing even stronger autofocusing. As the distance between two OVs increases, the focal intensity contrast would decrease, especially for a beam with positive launch angles, whose autofocusing property decreases much more quickly with the distance.
通过负发射角控制圆形艾里光束（CABs）的轨迹将大大降低其突然自聚焦特性。通过数值模拟具有不同初始发射角的圆形艾里涡旋光束的传播，我们在本文中证明，较大的光学涡旋（OV）拓扑电荷有助于在不同发射角（特别是负发射角）下增强突然自聚焦特性，而不影响焦点位置和轨迹。两个相反的光学涡旋在不同发射角下会相互吸引并在圆形艾里光束的焦平面中部分重叠，从而导致更强的自聚焦。随着两个光学涡旋之间距离的增加，焦点强度对比度会降低，特别是对于具有正发射角的光束，其自聚焦特性随距离下降得更快。
