Magneto-optical response enhanced by Mie resonances in nanoantennas

Control of light by an external magnetic field is one of the important methods for modulation of its intensity and polarisation. Magneto-optical effects at the nanoscale are usually observed in magnetophotonic crystals, nanostructured hybrid materials or magnetoplasmonic crystals. An indirect action of an external magnetic field (e.g. through the Faraday effect) is explained by the fact that natural materials exhibit negligible magnetism at optical frequencies. However, the concept of metamaterials overcome this limitation imposed by nature by designing artificial subwavelength meta-atoms that support a strong magnetic response, usually termed as optical magnetism, even when they are made of nonmagnetic materials. The fundamental question is what would be the effect of the interaction between an external magnetic field and an optically-induced magnetic response of metamaterial structures. Here we make the first step toward answering this fundamental question and demonstrate the multifold enhancement of the magneto-optical response of nanoantenna lattices due to the optical magnetism.Comment: 7 pages, 5 figure

The correlation between magneto-optical response and magnetic dipole resonance excitation in subwavelength silicon-nickel nanogratings

The advantages of gyrotopic materials are combined with the field of high-index metamaterials. The enhancement of the magneto-optical response in the spectral vicinity of the magnetic dipole resonance of a dielectric silicon nanodisks is numerically shown.This work was performed in Lomonosov Moscow State University and was supported by Russian Ministry of Education and Science (grant № 14. W03.31.0008

Intensity-dependent reflectance modulation of femtosecond laser pulses in GaAs nanocylinders with magnetic resonances

Abstract We experimentally demonstrate modulation of reflectance in periodic arrays of subwavelength gallium arsenide nanocylinders with Mie-type resonances due to absorption saturation and changes in the refractive index of the semiconductor material of metasurface. The intensity-dependent reflectance modulation of up to 30% in the vicinity of the magnetic dipole resonance at a low laser fluence below 200 μ J/cm 2 is shown by I-scan measurements

Efficient Light Coupling and Purcell Effect Enhancement for Interlayer Exciton Emitters in 2D Heterostructures Combined with SiN Nanoparticles

Optimal design of a silicon nitride waveguide structure composed of resonant nanoantennas for efficient light coupling with interlayer exciton emitters in a MoSe2–WSe2 heterostructure is proposed. Numerical simulations demonstrate up to eight times coupling efficiency improvement and twelve times Purcell effect enhancement in comparison with a conventional strip waveguide. Achieved results can be beneficial for development of on-chip non-classical light sources

Third-harmonic generation from photonic topological states in zigzag arrays of silicon nanodisks

We demonstrate the topology-controlled third-harmonic generation from photonic edge states in zigzag arrays of silicon nanodisks. The harmonic generation is observed only for one direction of the plane-wave excitation, manifesting nonlinearity-induced nonreciprocal nature of the photonic topological states.This work was supported by the Australian Research Council. Numerical calculations are supported by the Russian Science Foundation (grant no.16-19-10538). Fabrication was conducted at the Center for Nanophase Materials Sciences, being a DOE Office of Science User Facility. This material is based upon the work supported by the Air Force Office of Scientific Research under award number FA2386-16-1-0002

Manipulating the light intensity by magnetophotonic metasurfaces

We study numerically the possibility of controlling light properties by means of an external magnetic field. Considerable changes in the shape, value, and spectral position of the magneto-optical response are demonstrated in Voigt geometry for the transmitted light depending on the parameters of the magnetophotonic metasurface made up of nickel/silicon nanoparticles. The spectral overlapping of the fundamental magnetic and electric dipole Mie resonances leads to interference with a strong modification of phase relations, which manifests itself through an enhanced magneto-optical signal

Magneto-Optical Response Enhanced by Mie Resonances in Nanoantennas

We demonstrate both experimentally and numerically multifold enhancement of magneto-optical effects in subwavelength dielectric nanostructures with a magnetic surrounding exhibiting localized magnetic Mie resonances. We employ amorphous silicon nanodisks covered with a thin nickel film and achieve the 5-fold enhancement of the magneto-optical response of the hybrid magnetophotonic array of nanodisks in comparison with a thin nickel film deposited on a flat silica substrate. Our findings allow for a new basis for active and nonreciprocal photonic nanostructures and metadevices, which could be tuned by an external magnetic field

Magneto-optical effects from nanoparticles enhanced by mie resonances

Control of light by an external magnetic field is one of the important methods for modulation of its intensity and polarization. Magneto-optical effects at the nanoscale are usually observed in nanostructured hybrid materials or magnetoplasmonic crystals. In this work, we combine the advantages of all-dielectric resonant nanostructures and magnetic materials for creating compact active magneto-optical metadevices. High-index nanostructures offer novel opportunities for controlling light at the nanoscale based on a strong localization of both electric and magnetic fields in such structures near the corresponding Mie resonance [1]. This fact makes them similar to plasmonic nanostructures with clear advantage that all-dielectric meta-optics structures composed of nanoparticles with high refractive index can overcome this limit and initiate a new platform for nanophotonic metadevices [2]. As the important next step in this field, we consider a control of optical properties by an applied magnetic field, known to be an effective tool for many plasmonic structures [3,4]

Nonlinear Unidirectional Topological States in Zigzag Arrays of Bianisotropic Dielectric Nanoparticles

We generate a third-harmonic field from topological photonic edge states in zigzag arrays of silicon nanoparticles. The effect is unidirectional due to the interplay of nonlinearity and bianisotropic coupling between electric and magnetic Mie resonances

Nonlinear light generation in topological nanostructures

Topological photonics has emerged as a route to robust optical circuitry protected against disorder1,2 and now includes demonstrations such as topologically protected lasing3,4,5 and single-photon transport6. Recently, nonlinear optical topological structures have attracted special theoretical interest7,8,9,10,11, as they enable tuning of topological properties by a change in the light intensity7,12 and can break optical reciprocity13,14,15 to realize full topological protection. However, so far, non-reciprocal topological states have only been realized using magneto-optical materials and macroscopic set-ups with external magnets4,16, which is not feasible for nanoscale integration. Here we report the observation of a third-harmonic signal from a topologically non-trivial zigzag array of dielectric nanoparticles and the demonstration of strong enhancement of the nonlinear photon generation at the edge states of the array. The signal enhancement is due to the interaction between the Mie resonances of silicon nanoparticles and the topological localization of the electric field at the edges. The system is also robust against various perturbations and structural defects. Moreover, we show that the interplay between topology, bi-anisotropy and nonlinearity makes parametric photon generation tunable and non-reciprocal. Our study brings nonlinear topological photonics concepts to the realm of nanoscience.The authors acknowledge financial support from the Australian Research Council and the Strategic Fund of the Australian National University. A part of this research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. Numerical calculations were supported in part by the Ministry of Education and Science of the Russian Federation (Zadanie no. 3.2465.2017/4.6) and the Russian Foundation for Basic Research (grant no. 18-02-00381). A.P. and A.Sl. acknowledge partial support from the Russian Foundation for Basic Research (grant no. 18-32-20065). Y.K. thanks H. Atwater, B. Kanté, D. Leykam and E. Poutrina for discussions