Broadband infinite-Q plasmons enable intense Smith–Purcell radiation  

作　　者：ZI-WEN ZHANG CHAO-HAI DU YU-LU LEI JUAN-FENG ZHU PU-KUN LIU 

机构地区：[1]Center for Carbon-based Electronics,School of Electronics,Peking University,Beijing 100871,China [2]State Key Laboratory of Advanced Optical Communication Systems and Networks,School of Electronics,Peking University,Beijing 100871,China [3]Science,Mathematics and Technology(SMT),Singapore University of Technology and Design,Singapore 487372,Singapore

出　　处：《Photonics Research》2023年第11期1945-1958,共14页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(62271011,U21A20458);National Key Research and Development Program of China(2021YFA1600302);Beijing Science Foundation for Distinguished Young Scholars(JQ21011)。

摘　　要：With the rapid development of nanophotonics for enhancing free-electron radiation,bound states in the continuum(BICs)have emerged as a promising approach for emitting intense Smith–Purcell radiation(SPR)with enhanced intensity.However,current BIC-based methods are limited to single-frequency operation,thereby restricting their applications requiring spectral and angular tunability,such as particle detectors and light sources.To overcome this limitation,this work proposes an approach for constructing plasmonic BICs over a broad spectral range in symmetry-broken systems.By leveraging the high-Q resonances near the BICs,we achieve intense SPR with broadband tunability,potentially improving the radiation intensity by six orders compared to traditional methods.Experimentally,we validate the construction of BIC using plasmonic antennas and achieve broadband demonstration.Our proposed concept can be extended to other plasmonic or guided-wave systems,paving the way toward compact and efficient free-electron sources in hard-to-reach frequency regimes.

关 键 词：INTENSE INFINITE enable 

分 类 号：O53[理学—等离子体物理]