Active manipulation of radiated fields by a magnetoplasmonic half-wave dipole nanoantenna

Abstract

We demonstrate a concept for the active manipulation of radiated fields by a magnetoplasmonic half-wave dipole nanoantenna. Our idea comprises a two arms nanoantenna, made of metallic ferromagnetic cobalt–silver alloy (Co6Ag94), inspired by the analogous radio frequency half-wave dipole antenna design. Numerical results, obtained under the magnetization saturation condition, indicate a tilting of the radiated beam depending on the magnitude and sense of the magnetization of the ferromagnetic material. Significantly, we obtained tilting angles as large as ± 9.7 ∘ around the y axis for the magnetization placed along the x or z axes, respectively. Results in this work not only open up a new, to the best of our knowledge, way to dynamically manipulate the beam steering at the chip-scale, but also contribute to unveil novel magneto-optical effects at the nanoscale.

Goos–Hänchen Shift Spatially Resolves Magneto-Optical Kerr Effect Enhancement in Magnetoplasmonic Crystals

“…In comparison with the conventional TMOKE measurements, the maximum values of the spatially resolved TMOKE­( x ) are 2.6 times superior. Our findings can improve the functionality of magnetoplasmonic devices operating as sensors − and light modulators. − The spatially resolved magneto-optical effects associated with the GH shift can also be revealed in a wide range of nanophotonic devices such as magnetophotonic crystals, , plasmonic, , and low-loss all-dielectric metasurfaces. − Moreover, the observation of the GH shift can additionally boost the nonlinear magneto-optical, − ultrafast magnetoplasmonic, − and magnetoacoustic effects. , …”

Dynamic terahertz beamforming based on magnetically switchable hyperbolic materials

“…In particular, the unique feature of having ε ⊥ > 0 makes InSb slabs behave like high-refractive-index (HRI) dielectric media along those specific directions, which we exploit to produce magnetically tunable dipolar resonances. The latter produces an effect analogous to the case of nanoantennas [29][30][31], but in each unit cell of the metasurface. Therefore, we must find the geometric parameters at which the collective effects, through the constructive phase interference, produce the maximum beamforming.…”

“…Inspired by the use of magnetic fields to manipulate the optical radiated beams from magnetoplasmonic nanoantennas [29][30][31], we hypothesized that magnetic fields can also be employed for dynamic THz beamforming through magnetically tunable metasurfaces. In the THz range, Faraday and polar magneto-optical (MO) Kerr effects (PMOKE) were recently used for isolators and filters.…”