Broadband Enhancement of Faraday Effect Using Magnetoplasmonic Metasurfaces

Abstract

Magnetooptical Faraday effect enables ultrafast photonic devices based on nonreciprocal polarization rotation; however, the intrinsic weakness of Faraday effect prevents miniaturization and practical applications of nonreciprocal photonic devices. Magnetoplasmonics offers new mechanisms for enhancing magnetooptical effects using surface plasmon resonances, which generally have narrow bandwidths. Using finite-difference time-domain modelling, we demonstrate a magnetoplasmonic metasurface, which remarkably enhances the Faraday effect in a wide spectral range. While Faraday rotation in a bare bismuth-substituted yttrium iron garnet film is below 0.02° in the studied range of 600-1600 nm, the proposed metasurface yields few degrees of rotation in a broad band with a maximum exceeding 6.5°, which indicates about three orders of magnitude enhancement. We also show that by optimizing the configuration of the system including the geometry and excitation parameters, the metasurface response and operation band can be tuned further, and rotation values higher than 20° can be achieved. Finally, we present guidelines for designing magnetoplasmonic metasurfaces.

Enhancement of the polar magneto-optical Kerr effect with plasma hybrid microstructure

“…Hybridization with noble metal nanostructures is a promising route in recent years. For example, Kharratian et al 23 obtained a maximum exceeding 6.5 deg Faraday rotation angle at BIG with a thickness of only 10 nm and a broadband range of 600 to 1600 nm using a metasurface with hybrid noble metals, while the maximum rotation angle for a bare BIG film was <0.2 deg. On this basis, this work designed a magnetic plasma device with thinner thickness and smaller magnetic field, and studied the growth and changes of magneto optical Kerr rotation angle and reflectivity within a certain wavelength range.…”

“…Hybridization with noble metal nanostructures is a promising route in recent years. For example, Kharratian et al 23 . obtained a maximum exceeding 6.5 deg Faraday rotation angle at BIG with a thickness of only 10 nm and a broadband range of 600 to 1600 nm using a metasurface with hybrid noble metals, while the maximum rotation angle for a bare BIG film was <0.2 deg.…”

Active metasurface via magnetic control for tri-channel polarization multiplexing holography

“…The magneto-optical (MO) metasurface can provide multiple degrees of freedom for light control via magneto-optical effects, such as the Faraday effect [15][16][17] and Kerr effect [18,19] . This feature makes it widely applied in various fields such as modulator [20,21] , isolator [22][23][24] , chiral sensing [25,26] , biochemical sensing [27,28] , magnetic field sensing [29][30][31] , and MO switch [32,33] .…”

Magneto-optics of the 2D iron-garnet nanocylinder array with localized and lattice modes

“…27 For example magneto-plasmonic crystals offer an opportunity to increase the Faraday and Kerr effects due to excitation of surface plasmon polaritons. [28][29][30][31][32][33][34][35][36] The enhancement could be observed due to the excitation of plasmonic resonances in metallic particles or nanoantennas, [37][38][39][40] plasmonic nanocavities 41 and in the artificial metal-dielectric composites with hyperbolic dispersion. 42 The possibility of the magneto-optical effects enhancement was also reported for structures that maintain simultaneously several kinds of optical modes.…”