Structured light, especially beams carrying orbital angular momentum (OAM), has gained much interest due to its unique amplitude and phase structures. In terms of communication systems, multiple orthogonal OAM beams can be potentially utilized for increasing link capacity in different scenarios. This review describes challenges, advances, and perspectives on different aspects of the OAM-based optical communications, including (a) OAM generation/detection and (de)multiplexing, (b) classical free-space optical communication links, (c) fiber-based communication links, (d) quantum communication links, (e) OAM-based communications in different frequency ranges, (f) OAM-based communications using integrated devices, and (g) novel structured beams for communications.

中文翻译：

---

用于通信的光的轨道角动量

结构光，尤其是携带轨道角动量 (OAM) 的光束，因其独特的振幅和相位结构而备受关注。在通信系统方面，多个正交 OAM 波束可以潜在地用于增加不同场景中的链路容量。本综述描述了基于 OAM 的光通信不同方面的挑战、进展和前景，包括 (a) OAM 生成/检测和（解）复用，(b) 经典自由空间光通信链路，(c) 光纤-基于通信链路，(d) 量子通信链路，(e) 不同频率范围内基于 OAM 的通信，(f) 使用集成设备的基于 OAM 的通信，以及 (g) 用于通信的新型结构波束。