Electromagnetic waves carrying orbital angular momentum(OAM),namely OAM beams,are important in various fields including optics,communications,and quantum information.However,most current schemes can only generate sing...Electromagnetic waves carrying orbital angular momentum(OAM),namely OAM beams,are important in various fields including optics,communications,and quantum information.However,most current schemes can only generate single or several simple OAM modes.Multi-mode OAM beams are rarely seen.This paper proposes a scheme to design metasurfaces that can generate multiple polarization-multiplexed OAM modes with equal intervals and intensities(i.e.,OAM combs)working in the terahertz(THz)range.As a proof of concept,we first design a metasurface to generate a pair of polarization-multiplexed OAM combs with arbitrary mode numbers.Furthermore,another metasurface is proposed to realize a pair of polarization-multiplexed OAM combs with arbitrary locations and intervals in the OAM spectrum.Experimental results agree well with full-wave simulations,verifying a great performance of OAM combs generation.Our method may provide a new solution to designing high-capacity THz devices used in multi-mode communication systems.展开更多
基金support from the National Key Research and Development Program of China(No.2019YFA0210203)the National Natural Science Foundation of China(No.62271011,No.61971013).
文摘Electromagnetic waves carrying orbital angular momentum(OAM),namely OAM beams,are important in various fields including optics,communications,and quantum information.However,most current schemes can only generate single or several simple OAM modes.Multi-mode OAM beams are rarely seen.This paper proposes a scheme to design metasurfaces that can generate multiple polarization-multiplexed OAM modes with equal intervals and intensities(i.e.,OAM combs)working in the terahertz(THz)range.As a proof of concept,we first design a metasurface to generate a pair of polarization-multiplexed OAM combs with arbitrary mode numbers.Furthermore,another metasurface is proposed to realize a pair of polarization-multiplexed OAM combs with arbitrary locations and intervals in the OAM spectrum.Experimental results agree well with full-wave simulations,verifying a great performance of OAM combs generation.Our method may provide a new solution to designing high-capacity THz devices used in multi-mode communication systems.
