Nonlinear Fano-Resonant Dielectric Metasurfaces

Abstract

Man-made structural colors, which originate from resonant interactions between visible light and manufactured nanostructures, are emerging as a solution for ink-free color printing. We show that non-iridescent structural colors can be conveniently produced by nanostructures made from high-index dielectric materials. Compared to plasmonic analogs, color surfaces with high-index dielectrics, such as germanium (Ge), have a lower reflectance, yielding a superior color contrast. Taking advantage of band-to-band absorption in Ge, we laser-postprocess Ge color metasurfaces with morphology-dependent resonances. Strong on-resonance energy absorption under pulsed laser irradiation locally elevates the lattice temperature (exceeding 1200 K) in an ultrashort time scale (1 ns). This forms the basis for resonant laser printing, where rapid melting allows for surface energy-driven morphology changes with associated modification of color appearance. Laser-printable high-index dielectric color metasurfaces are scalable to a large area and open a new paradigm for printing and decoration with nonfading and vibrant colors.

Large optical nonlinearity of nanoantennas coupled to an epsilon-near-zero material

“…Thus, all-optical active devices tend to have large footprints, which limits the integration density to many orders of magnitude smaller than what can be achieved in a state-of-the-art electronic integrated circuits [1,2]. Thus, materials with much stronger nonlinear optical responses are needed in order to enable integrated high-density on-chip nonlinear optical devices.Over the years several approaches have been explored to enhance the intrinsic nonlinear optical response of materials, including local field enhancement using composite structures [3,4,5], plasmonic structures [6,7], and metamaterials [8,9,10,11]. However, these techniques offer only limited control over the magnitude (and sign when applicable) of the wavelength-dependent nonlinear response, and typically involve a trade-off between the strength of the nonlinearity and the spectral position of the peak nonlinear response.…”

“…Over the years several approaches have been explored to enhance the intrinsic nonlinear optical response of materials, including local field enhancement using composite structures [3, 4,5], plasmonic structures [6,7], and metamaterials [8,9,10,11]. However, these techniques offer only limited control over the magnitude (and sign when applicable) of the wavelength-dependent nonlinear response, and typically involve a trade-off between the strength of the nonlinearity and the spectral position of the peak nonlinear response.…”

All-dielectric phase-change reconfigurable metasurface

“…A wide range of passive alldielectric metasurface planar optical elements for steering, splitting, filtering, focusing and variously manipulating beams have been demonstrated, very typically using silicon for visible to near-IR wavelengths. [13][14][15][16][17] Active functionalities have been demonstrated on the basis of hybridization of a silicon metasurface with a liquid crystal, 18 two photon absorption on silicon metasurfaces 19,20 and nonlinear optomechanical reconfiguration in a free-standing silicon membrane metasurface. 21 By virtue of their compositionally-controlled high-index, low-loss characteristics, which extend over a broad spectral range from the visible to long-wave infrared, and can moreover be reversibly switched (electrically or optically) in a non-volatile fashion, the chalcogenides (binary and ternary sulphides, selenides, and tellurides) provide an exceptionally adaptable material base for the realization of optically reconfigurable meta-devices.…”

All-Dielectric Nanophotonics: Fundamentals, Fabrication, and Applications

“…Therefore, implementation of plasmonic principles for developing of all-dielectric nonlinear nanodevices looks tempting. Recently, the enhancement of optical nonlinearities in resonant Si nanostructures has been demonstrated theoretically and experimentally at the scale of single nanoparticles [58][59][60][61][194][195][196][197].…”

“…The efficiency of IR-to-visible conversion by 2 orders of magnitude in the vicinity of the magnetic dipole resonance with respect to the unstructured bulk Si slab was achieved. The idea of the conversion enhancement at the magnetic resonance has been developed in subsequent works with regard to the generation of higher optical harmonics [128,196,198,199] and Raman scattering [30]. Dielectric oligomers [198] and nanoparticles supporting the anapole mode excitation [200] have also been employed for third harmonic generation enhancement.…”