Resonant Beam Communications: Principles and Designs

Wireless optical communications (WOC) has carriers up to several hundred terahertz, which offers several advantages, such as ultrawide bandwidth and no electromagnetic interference. Conventional WOC that uses light transmitters such as light emitting diodes (LEDs), directed LEDs, and lasers are facing major challenges in attenuation or tracking. Resonant beam communications (RBCom) meets the requirements of low attenuation, non-mechanical mobility, and multiple access. Yet, RBCom channel undergoes echo interference in contrast to common non-echo channels. An interference elimination method based on optical filtering is presented along with an exemplary interference-free RBCom system.