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 technologies that use 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. However, 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.
Bibliographical noteFunding Information:
TheworkofM.XiongandQ.Liu was supported by the National NaturalScienceFoundationof China under Grant 61771344. The work of G. Wang and G. B. Giannakis was supported par tially by NSG grants 1505970, 1711471, and 1901134. The work of C. Huang was support ed by the National Key R&D Program of China under Grant 2018YFB1800800.