轨道角动量(OAM)是具有螺旋相位的光束的自然属性,且不同拓扑荷的OAM光束之间相互正交。利用OAM光束的这种特性,可以把OAM光束作为一种新的信息载体应用到复用技术之中。OAM复用技术在不需要额外带宽的情况下可以极大提升信道容量和频谱效率。光纤作为一种优良的传输介质,是现代通信网络中的首选,基于光纤传输的OAM复用技术引起了研究者的广泛关注。介绍了轨道角动量的基本原理,讨论了适于携带OAM光束传输的光纤、OAM光束的生成与检测方法、OAM复用技术相关器件及其复用系统实验等方面的研究进展,最后探讨了现有技术存在的问题和发展趋势。

Orbital angular momentum (OAM) is a natural property of beams with spiral phase. OAM beams with different topological charges are mutually orthogonal. OAM beams can be applied to OAM multiplexing as a new information carrier based on their orthogonality. OAM multiplexing greatly improves the channel capacity and spectrum efficiency without additional bandwidth. Owning to its excellent properties, optical fiber has become the best choice in modern communication network. OAM multiplexing based on optical fiber has attracted widespread concern of researchers. We introduce the basic principle of OAM firstly, and then discuss the research progress of the optical fiber, which is suitable for carrying OAM beam, OAM beam generation and detection methods, related devices and experiments of OAM multiplexing technology and so on. Finally, the existing problems and trends of the current technologies are discussed.