Circular Displacement Current Induced Anomalous Magneto‐Optical Effects in High Index Mie Resonators

Abstract

Dielectric Mie nanoresonators showing strong light-matter interaction at the nanoscale may enable new functionality in photonic devices, such as strong magneto-optical effects. However, most reports so far have been focused on the enhancement of conventional magneto-optical effects. Here, anomalous magneto-optical effects are observed in high-index-contrast Si/Ce:YIG/YIG/SiO 2 Mie resonators. In particular, giant modulation of light intensity in transverse magnetic configuration up to 6.4% under s-polarized incidence appears, which is non-existent in planar magneto-optical thin films. A large rotation of transmitted light polarization in longitudinal magnetic configuration is also observed, which is two orders of magnitude higher than for planar magneto-optical thin films. These phenomena are originated from the unique circular displacement current when exciting magnetic resonances in the Mie resonators, which change the electric field direction locally. This work indicates an uncharted territory of light polarization control based on complex modal profiles in all-dielectric magneto-optical Mie resonators and metasurfaces.

Enhancement of the Faraday Effect and Magneto-optical Figure of Merit in All-Dielectric Metasurfaces

“…The magnetic field is enhanced in the Si disk, and the electric field induces circular displacement currents, whereas the electric field distribution at λ = 1420 nm shows the electric dipole (ED) resonance behavior, with E-field being concentrated in the disk. The electric displacement vector is parallel to the x direction. , The multipole analysis results for single silicon nanodisks embedded in homogeneous medium also confirm the existence of MD and ED Mie resonances . Combining these characteristics, the modes excited in the metasurfaces are considered to be a hybridized Mie resonance and waveguide modes, namely, TM0-MD and TE0-ED modes, respectively …”

The 2022 magneto-optics roadmap

“…Excitation of guided modes propagating at various angles to the light incidence plane and medium magnetization originates a novel MO intensity effect observed both in p-and s-polarizations whereas a smooth film produces no such effect for s-polarization [164] (figure 19(a)). Similar effect is observed if excitation of localized resonances provides an efficient gyromagnetic response [170]. Under the simultaneous excitation of the TM and transverse electric (TE) modes, longitudinal magnetic field mediates their coupling leading to significant growth of the longitudinal Kerr effect (up to 1 • ) even for small angles of incidence of less than 1 • [165,170] (figure 19(b)).…”

“…Initially, ADMOMSs were proposed theoretically [161,162] and were recently demonstrated on the basis of magnetic dielectrics arranged in periodic arrays of trenches or nanodisks [163][164][165][166][167][168][169][170]. Several unusual effects were shown to arise in ADMOMS.…”

Coupling Controlled Dual‐Band Tunable Electromagnetic Extraordinary Transmission in Graphene Hybrid Metasurfaces

“…[9][10][11][12] The metasurfaces with simple planar structures made of conventional metallic and dielectric materials have been used to manipulate EM wave in the amplitude, phase and polarization and complex wavefronts. [13][14][15][16][17][18][19][20][21][22][23][24] However, the operation frequency and performance of the metasurfaces made of conventional metallic/dielectric is limited in a narrow frequency range due to the static characteristic of the constituent materials. The static and narrowband function of metasurface may obstacle the practical applications.To overcome the static response, the fixed and narrow operation band of conventional metasurface, there have been various metadevices incorporated with materials or components responding to external stimuli such as electric elements, semiconductors, 2D materials, and perovskite materials [25][26][27][28][29][30][31] for tunable or multiple functionalities.…”

“…[9][10][11][12] The metasurfaces with simple planar structures made of conventional metallic and dielectric materials have been used to manipulate EM wave in the amplitude, phase and polarization and complex wavefronts. [13][14][15][16][17][18][19][20][21][22][23][24] However, the operation frequency and performance of the metasurfaces made of conventional metallic/dielectric is limited in a narrow frequency range due to the static characteristic of the constituent materials. The static and narrowband function of metasurface may obstacle the practical applications.…”