Smith-Purcell radiation emission in aperiodic arrays

Abstract

We study the Smith-Purcell light emission produced by electrons moving parallel to linear aperiodic particle arrays. This constitutes a generalization of this type of phenomenon from periodic to aperiodic structures. Like in the periodic case, the emission is found to exhibit intense features in its angular and frequency distributions, associated with the condition of constructive interference between the contributions arising from different particles in the array. This condition can also be expressed in terms of momentum conservation involving reciprocal wave-vector transfers from the array. We consider two examples of quasiperiodic and hyperuniform aperiodic arrays that allow us to illustrate this idea. Our study opens a new unexplored direction in the interaction of fast electrons with aperiodic arrays characterized by strong features in reciprocal space, which dominate the electron-array interaction.

Spectrally and Spatially Resolved Smith-Purcell Radiation in Plasmonic Crystals with Short-Range Disorder

“…In general, photonic crystals have shown a wealth of Smith-Purcell-like effects [5,[26][27][28], with some papers even predicting that photonic crystals will enhance the conventional Smith-Purcell radiation beyond what is possible with regular diffraction gratings [26]. A very recent theoretical work investigated the Smith-Purcell effect in aperiodic structures [29]. Furthermore, other theoretical studies have predicted the enhancement of SmithPurcell radiation arising from plasmonic crystals (e.g., Refs.…”

Spectral and spatial shaping of Smith-Purcell radiation

“…Even more advanced theories revealing quantum features of this effect [13,14] assumed simple periodic structures, giving a momentum n 2π x to the incoming electron (where n and are the diffraction order and grating period, respectively). Recently, the study of SPR was extended beyond the simple periodic structure, into aperiodic arrays [15], disordered plasmonic arrays [16], and Babinet metasurfaces for manipulating the SPR polarization [17]. However, to the best of our knowledge, no attempt has been made to shape the angular spectrum and frequency spectrum of SPR.…”

Manipulating Cherenkov Radiation and Smith–Purcell Radiation by Artificial Structures

“…The surface plasmon induced by the moving electrons could increase the terahertz radiation intensity up to ten orders of magnitude compared to the radiation from a dielectric grating. Recently, a theoretical work indicated that Smith–Purcell radiation can occur in aperiodic structures . Soon after, Kaminer et al adopted an innovative experimental setup based on a scanning electron microscope to observe collective Smith–Purcell emission from the 2D plasmonic crystal with strong disorder .…”