Wan Chenhao, Chen Jian, Chong Andy, Zhan Qiwen
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Department of Electro-Optics and Photonics, University of Dayton, Dayton, OH 45469, USA.
Natl Sci Rev. 2021 Aug 16;9(7):nwab149. doi: 10.1093/nsr/nwab149. eCollection 2022 Jul.
Vortices are whirling disturbances, commonly found in nature, ranging from tremendously small scales in Bose-Einstein condensations to cosmologically colossal scales in spiral galaxies. An optical vortex, generally associated with a spiral phase, can carry orbital angular momentum (OAM). The optical OAM can either be in the longitudinal direction if the spiral phase twists in the spatial domain or in the transverse direction if the phase rotates in the spatiotemporal domain. In this article, we demonstrate the intersection of spatiotemporal vortices and spatial vortices in a wave packet. As a result of this intersection, the wave packet hosts a tilted OAM that provides an additional degree of freedom to the applications that harness the OAM of photons.
涡旋是一种旋转扰动，在自然界中普遍存在，其尺度范围极大，从玻色 - 爱因斯坦凝聚体中的极小尺度到螺旋星系中的宇宙尺度。光学涡旋通常与螺旋相位相关联，能够携带轨道角动量（OAM）。如果螺旋相位在空间域中扭曲，光学OAM可以是纵向的；如果相位在时空域中旋转，则光学OAM可以是横向的。在本文中，我们展示了波包中时空涡旋和空间涡旋的交叉。这种交叉的结果是，波包拥有一个倾斜的OAM，为利用光子OAM的应用提供了额外的自由度。
