ИСТИНА

Mie-resonant nanophotonic structures made of dielectric and semiconductor materials with high refractive indices are considered as a promising platform for novel functional optical devices [1–2]. To make such structures active different mechanisms have been proposed recently [3–4]. All-optical switching based on photo-induced carrier generation manifests itself as one of the most promising techniques owing to the intrinsic ultrafast speed of this process [5]. However, most experimental demonstrations to date are limited by transmittance or reflection changes missing active beam profile control by such nanophotonic structures. In this work two different studies of Mie-resonant nanophotonic structures integrated with 2D materials are presented. The first one considers a high-Q resonant metasurface combined with a monolayer TMD film. The metasurface comprises a set of TiO2 nanodisks arranged in a tightly spaced quadratic lattice on a silica substrate. MoSe2 monolayer is transferred on top of the nanostructure by the mechanical exfoliation technique. Experimental SHG characterization conducted at room and cryogenic temperatures reveals non-trivial interplay between volumetric (associated with the metasurface) and material (associated with the TMD film) resonances in the structure leading to the multifold increase of the observed nonlinear effect. The second study considers integrated silicon waveguides composed of resonant nanoparticles and thin films of 2D materials. We demonstrate that excitation of magnetic Mie-type resonances in such waveguide chains of Si nanoparticles can increase on-chip light coupling efficiency for localized dipole sources in thin InSe films [8]. Particularly, we experimentally observe up to 2 times improvement in comparison with conventional silicon waveguides. Finally, we investigate a resonant waveguide system composed of SiN nanoparticles for effective optical coupling with localized interlayer exciton emitters in vertically stacked monolayer MoSe2–WSe2 heterostructures [9]. Numerically we demonstrate up to 8 times radiation coupling efficiency improvement and up to 12 times Purcell effect enhancement in comparison with the conventional silicon strip waveguide. Achieved results can be beneficial for development of on-chip light sources. [1] A. Kuznetsov et al., “Optically resonant dielectric nanostructures,” Science, 354, aaf2472 (2016). [2] R. Mupparapu et al., “Integration of two-dimensional transition metal dichalcogenides with Mie-resonant dielectric nanostructures”, Adv. Phys.: X, 5, 1734083 (2020). [3] K. Koshelev et al., “Asymmetric Metasurfaces with High-Q Resonances Governed by Bound States in the Continuum”, Phys. Rev. Lett., 121, 193903 (2018). [4] N. Bernhardt et al., “Quasi-BIC Resonant Enhancement of Second-Harmonic Generation in WS2 Monolayers”, Nano Lett., 20, 5309–5314 (2020). [5] G. Wang et al., “Giant Enhancement of the Optical Second-Harmonic Emission of WSe2 Monolayers by Laser Excitation at Exciton Resonances”, Phys. Rev. Lett., 114, 097403 (2015) [6] R. Bakker et al., “Resonant Light Guiding Along a Chain of Silicon Nanoparticles”, Nano Lett., 17, 3458–3464 (2017). [7] Y. Sirmaci et al., “All-dielectric Huygens’ meta-waveguides for resonant integrated photonics”, Laser Photonics Rev., 17, 2200860 (2023). [8] A. Gartman et al., “Efficient integration of single-photon emitters in thin InSe films into resonance silicon waveguides”, JETP Lett., 112, 693–698 (2020). [9] A. Gartman et al., “Efficient Light Coupling and Purcell Effect Enhancement for Interlayer Exciton Emitters in 2D Heterostructures Combined with SiN Nanoparticles”, Nanomaterials, 13, 1821 (2023).