Anapole Mode Sustaining Silicon Metamaterials in Visible Spectral Range

Abstract

This paper is dedicated to a type of perforated silicon metamaterials, possessing anapole mode in visible spectral range due to destructive interference between electric and toroidal dipole moments. The proposed structure gains both in attainable material and simplified fabrication. Such a material exhibits a desirable physical effect and has obvious practical application: it supports the anapole mode without complicated 3D toroidal geometry and can be processed in one step by nanofabrication methods. The metamaterial paves the way for advanced optical devices on the base of all‐dielectric metamaterials. Besides inherently low dissipative losses and strong anapole response, such an optical metamaterial can demonstrate subtle sensing, nonradiative data transfer, Aharonov‐Bohm effect and other tempting applications in nanophotonics.

Nonradiating photonics with resonant dielectric nanostructures

“…Complex wave mixing effects were also considered by using non radiating states in [128], which reported Four Wave Mixing (FWM) in a similar structure of [109], and composed of a germanium nanodisk (200 nm of thickness and 625 nm of radius) in which two incident waves at different frequencies ( 1 and 2 ) give rise to four waves (3 1 , [38,117,[121][122][123][124].…”

“…The design of a metasurface supporting anapole modes in the visible range was proposed recently by Ospanova and co-workers [117], relying on a metasurface composed of a perforated 100 nm thick Si layer and represented in Fig. 5a.…”

Can a Nonradiating Mode Be Externally Excited? Nonscattering States versus Embedded Eigenstates

“…Introduction -The ability to tailor optical scattering in anomalous and extreme ways, beyond what is achievable with conventional optical materials and structures, has been for several years one of the fundamental goals of optical metamaterials and nanophotonic systems [1]. Rapid progress in these fields has enabled the realization of a plethora of anomalous scattering effects, including invisibility [2][3][4][5][6], ultra-sharp Fano scattering resonances [7,8], non-scattering anapole scatterers [9][10][11][12][13][14][15][16], and bound states in the continuum or embedded eigenstates [17][18][19][20][21][22]. Scattering engineering plays a fundamental role in modern photonics research, for applications spanning from wavefront manipulation [23] and optical signal processing [24,25], to energy harvesting [26] and sensing [27], to mention just a few.…”

“…This growing area of research holds the potential to enable important advances in nanophotonics and quantum optics, for extreme light confinement in small open structures. Intriguingly, recent works (e.g., [9][10][11][12][13][14][15][16]) have discussed the possibility to observe and excite radiationless anapole modes supported by engineered scatterers.…”

Toroidal Dipole Mode Observation In Situ

“…[14][15][16][17][18][19][20][21][22] Apparently, the main interest on toroidal moment is underpinned by their contribution to more promising anapole mode excitations that take place due to destructive interference between electric and toroidal multipoles of the same order, leading to such effects as strong field localization inside the even point-like sources and invisibility to external observer. [10][11][12][13]17,[23][24][25][26][27][28][29][30][31][32] The works of the last decade point out to feasibility of this effect in structures from microwaves to optics and demonstrate such effects as novel types of transparency, [23] optical invisibility, [27,33] and cloaking. [34] These properties are promising since they open the way to novel sensing, modulating techniques, switching possibility between multipoles, high Q-factor resonance of Fano types, and demonstration of planar THz metamaterials as 2D Ising model.…”