Free-space optical (FSO) systems are able to offer the high data-rate, secure, and cost-efficient communication links required for applications such as wireless front- and backhauling for 5G and 6G communication networks. Despite the substantial advancement of FSO systems over the past decades, the requirement of a line-of-sight connection between transmitter and receiver remains a key limiting factor for their deployment. In this article, we discuss the potential role of intelligent reflecting surfaces (IRSs) as a solution to relax this requirement. We present an overview of existing optical IRS technologies; compare optical IRSs with radio frequency IRSs and optical relays; and identify various open problems for future research on IRS-assisted FSO communications.

中文翻译：

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智能反射面辅助自由空间光通信


自由空间光学 (FSO) 系统能够提供 5G 和 6G 通信网络的无线前传和回程等应用所需的高数据速率、安全且经济高效的通信链路。尽管 FSO 系统在过去几十年中取得了巨大进步，但发射器和接收器之间的视距连接要求仍然是其部署的关键限制因素。在本文中，我们讨论了智能反射表面 (IRS) 作为放宽这一要求的解决方案的潜在作用。我们概述了现有的光学 IRS 技术；将光学 IRS 与射频 IRS 和光继电器进行比较；并确定 IRS 协助的 FSO 通信未来研究的各种未决问题。