Free-electron-driven orbital angular momentum emitter

Zhu, Juan-Feng and Du, Chao-Hai and Zhang, Zi-Wen and Li, Fan-Hong and Liu, Pu-Kun and Cross, Adrian W. and Zhang, Liang; (2020) Free-electron-driven orbital angular momentum emitter. In: 2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies, UCMMT 2020. 2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies, UCMMT 2020 . Institute of Electrical and Electronics Engineers Inc., CHN. ISBN 9781728190648

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    Abstract

    A free-electron-driven orbital angular momentum (OAM) emitter is introduced in this paper. When the free electron passes over the cylindrical grating, the spoof surface plasmon (SSP) is stimulated in this system. With loading a helical wire which induces a gradient azimuthal phase distribution the system, the SSP mode will be converted into the spatial OAM radiation. The operating frequency of the OAM mode can be tuned by the electron beam energy of the surface plasmon. Compared with the Smith-Purcell radiation from the helical grating, the field intensity is enhanced by about 50 times. This method provides an efficient way to generate the OAM mode, and may find applications in a communication system.

    ORCID iDs

    Zhu, Juan-Feng, Du, Chao-Hai, Zhang, Zi-Wen, Li, Fan-Hong, Liu, Pu-Kun, Cross, Adrian W. ORCID logoORCID: https://orcid.org/0000-0001-7672-1283 and Zhang, Liang ORCID logoORCID: https://orcid.org/0000-0002-6317-0395;