Retro-Reflective Beam Communications With Spatially Separated Laser Resonator

Optical wireless communications (OWC) utilizing infrared or visible light as the carrier attracts great attention in 6G research. Resonant beam (RBCom) is an OWC technology which simultaneously satisfies needs of non-mechanical mobility and high signal-to-noise ratio~(SNR). It has self-alignment feature therefore avoids positioning pointing operations. However, RBCom undergoes echo interference. Here we propose echo-interference-free system design based on second harmonic generation. The transmitter receiver constitute a spatially separated laser resonator, retro-reflective resonant formed tracks automatically. This structure provides channel with adaptive capability beamforming alignment, similar to concept intelligent reflecting surface (IRS) enhanced communications, but without hardware software controllers. Besides, establish analytical model evaluate radius, power, capacity. results show that our achieves longer distance smaller diameter for transmission beyond 10 Gbit/s, compared existing technologies.