Resonant beam communications (RBCom), which adopts oscillating photons between two separate retroreflectors for information transmission, exhibits potential advantages over other types of wireless optical communicatio...Resonant beam communications (RBCom), which adopts oscillating photons between two separate retroreflectors for information transmission, exhibits potential advantages over other types of wireless optical communications (WOC). However, echo interference generated by the modulated beam reflected from the receiver affects the transmission of the desired information. To tackle this challenge, a synchronization-based point-to-point RBCom system is proposed to eliminate the echo interference, and the design for the transmitter and receiver is discussed. Subsequently,the performance of the proposed RBCom is evaluated and compared with that of visible light communications(VLC)and free space optical communications (FOC). Finally, future research directions are outlined and several implementation challenges of RBCom systems are highlighted.展开更多
The wavefront control of spin or orbital angular momentum(OAM)is widely applied in the optical and radio fields.However,most passive metasurfaces provide limited manipulations,such as the spin-locked wavefront,a stati...The wavefront control of spin or orbital angular momentum(OAM)is widely applied in the optical and radio fields.However,most passive metasurfaces provide limited manipulations,such as the spin-locked wavefront,a static OAM combination,or an uncontrollable OAM energy distribution.We propose a reflection-type multi-feed metasurface to independently generate multi-mode OAM beams with dynamically switchable OAM combinations and spin states,while simultaneously,the energy distribution of carrying OAM modes is controllable.Specifically,four elements are proposed to overcome the spin-locked phase limitation by combining propagation and geometric phases.The robustness of these elements is analyzed.By involving the amplitude term and multi-feed technology in the design process,the proposed metasurface can generate OAM beams with a controllable energy distribution over modes and switchable mode combinations.OAM-based radio communication with four independent channels is experimentally demonstrated at 14 GHz by employing a pair of the proposed metasurfaces.The powers of different channels are adjustable by the provided amplitude term,and the maximum crosstalk is−9 dB,proving the effectiveness and practicability of the proposed method.展开更多
基金supported in part by the Natural Science Foundation of China under Grant 62341112in part by the Basic Research Project of Hetao Shenzhen-HK S&T Cooperation Zone under Grant HZQBKCZYZ-2021067+3 种基金in part by the Key Project of Shenzhen under Grant JCYJ20220818103006013in part by Shenzhen High-Tech Zone Project under Grant KC2022KCCX0041in part by Guangdong Provincial Key Laboratory of Future Networks of Intelligence under Grant 2022B1212010001in part by Shenzhen Key Laboratory of Big Data and Artificial Intelligence under Grant ZDSYS201707251409055.
文摘Resonant beam communications (RBCom), which adopts oscillating photons between two separate retroreflectors for information transmission, exhibits potential advantages over other types of wireless optical communications (WOC). However, echo interference generated by the modulated beam reflected from the receiver affects the transmission of the desired information. To tackle this challenge, a synchronization-based point-to-point RBCom system is proposed to eliminate the echo interference, and the design for the transmitter and receiver is discussed. Subsequently,the performance of the proposed RBCom is evaluated and compared with that of visible light communications(VLC)and free space optical communications (FOC). Finally, future research directions are outlined and several implementation challenges of RBCom systems are highlighted.
基金Project supported by the National Natural Science Foundation of China(Nos.61971115,61721001,61975177,61971099)。
文摘The wavefront control of spin or orbital angular momentum(OAM)is widely applied in the optical and radio fields.However,most passive metasurfaces provide limited manipulations,such as the spin-locked wavefront,a static OAM combination,or an uncontrollable OAM energy distribution.We propose a reflection-type multi-feed metasurface to independently generate multi-mode OAM beams with dynamically switchable OAM combinations and spin states,while simultaneously,the energy distribution of carrying OAM modes is controllable.Specifically,four elements are proposed to overcome the spin-locked phase limitation by combining propagation and geometric phases.The robustness of these elements is analyzed.By involving the amplitude term and multi-feed technology in the design process,the proposed metasurface can generate OAM beams with a controllable energy distribution over modes and switchable mode combinations.OAM-based radio communication with four independent channels is experimentally demonstrated at 14 GHz by employing a pair of the proposed metasurfaces.The powers of different channels are adjustable by the provided amplitude term,and the maximum crosstalk is−9 dB,proving the effectiveness and practicability of the proposed method.
