Time, polarization, and wavelength multiplexing schemes have been used to satisfy the growing need of transmission capacity. Using space as a new dimension for communication systems has been recently suggested as a versatile technique to address future bandwidth issues. We review the potentials of harnessing the space as an additional degree of freedom for communication applications including free space optics, optical fiber installation, underwater wireless optical links, on-chip interconnects, data center indoor connections, radio frequency, and acoustic communications. We focus on the orbital angular momentum (OAM) modes and equally identify the challenges related to each of the applications of spatial modes and the particular OAM modes in communication. We further discuss the perspectives of this emerging technology. Finally, we provide the open research directions and discuss the practical deployment of OAM communication links for different applications.

中文翻译：

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使用空间模式复用进行通信：潜力、挑战和前景

时间、极化和波长复用方案已被用于满足不断增长的传输容量需求。最近有人建议将空间作为通信系统的新维度作为解决未来带宽问题的通用技术。我们回顾了利用空间作为通信应用的额外自由度的潜力，包括自由空间光学、光纤安装、水下无线光链路、片上互连、数据中心室内连接、射频和声学通信。我们专注于轨道角动量 (OAM) 模式，并同样确定与空间模式和特定 OAM 模式在通信中的每个应用相关的挑战。我们进一步讨论了这一新兴技术的前景。最后，