講題:Generation of light beams by electron beam
excited surface plasmons 摘要:When the electron beam moves along
or normally onto the plasmonic nanostructures (PNs), it can excite the surface
plasmons (SPs) on PNs along with the transition radiation (TR). In the former
case, the SPs have specific frequencies determined by the intersection of
dispersion curves of electron beam and SPs. In the latter case, conversely, the
SPs have a wide frequency band [1]. Furthermore, SPs can be transferred into
light emission (SP emission) by the surface structures of PNs. In this work, we
will consider three types of light beam generation by electron beam excited
SPs. First, we will investigate SP-manipulated and localized SP
(LSP)-manipulated Smith-Purcell radiation (SPR) on metallic periodic gratings
and disk arrays, respectively [2]. The SPR can be enhanced by exciting SPs and
LSPs if their frequencies are within the emission bands of SPRs. Second, the
generation of convergent beam by electron-excited SPs is examined. Here the
mechanism of SPR on metallic chirped gratings is proposed to generate the
convergent light beam. Finally, the SP-manipulated TR and SP emission from the
electron beam normally incident PNs with designed slit structures are studied
[3]. This work offers potential applications in the fields of optical imaging,
holography, cryptography and tunable visible light source, etc.
[1] S. Gong, M. Hu, R. Zhong, X. Chen, P. Zhang, T. Zhao and S. Liu, “Electron beam excitation of surface plasmon polaritons,” Opt. Express 22, 19252-19261 (2014). [2] Y. C. Lai, T. C. Kuang, B. H. Cheng, Y. C. Lan and D. P. Tsai, “Generation of convergent light beams by using surface plasmon locked Smith-Purcell radiation,” Scientific Reports 7, 11096 (2017). [3] T. Coenen, B. J. M. Brenny, E. J. Vesseur and A. Polman, “Cathodoluminescence microscopy: Optical imaging and spectroscopy with deep-subwavelength resolution,” MRS Bulletin 40(4), 359-365 (2015). |
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