• Zerush@lemmy.ml
    link
    fedilink
    English
    arrow-up
    5
    ·
    1 day ago

    Asking Andisearch

    Dramatic and Elusive Resonant Lattice Kerker Effect in the Nonlinear Response of Plasmonic Lattices

    Key Points

    • A plasmonic metasurface demonstrates the resonant lattice Kerker effect, suppressing reflection in a narrow spectral band through simultaneous electric dipole and lattice mode excitation.
    • The effect is observed in the nonlinear optical response of periodic plasmonic structures, making it both rare and difficult to achieve experimentally.

    This research describes a plasmonic metasurface that supports the resonant lattice Kerker effect, which manifests as suppressed reflection within a narrow spectral range. The suppression occurs because electric dipole and magnetic-type lattice resonances are excited simultaneously, causing their radiated fields to interfere destructively in the backward direction, per Wiley Online Library.

    Dramatic and Elusive Resonant Lattice Kerker Effect in the Nonlinear Response of Plasmonic Lattices Image: Wiley Online Library - Dramatic and Elusive Resonant Lattice Kerker Effect in the Nonlinear Response of Plasmonic Lattices

    Background and Context

    The Kerker effect, in its classical form, describes conditions under which a particle’s forward and backward scattering become asymmetric due to the interplay of electric and magnetic multipoles. The “first Kerker condition” produces zero backscattering when electric and magnetic dipole moments are equal in magnitude and phase. Achieving this in practice, particularly in plasmonic systems and at nonlinear frequencies, has proven difficult.

    Full Color Generation Using Silver Tandem Nanodisks Image: ACS Publications - Full Color Generation Using Silver Tandem Nanodisks

    Periodic plasmonic arrays (lattices) add another layer of physics. Wood’s anomalies and lattice resonances can hybridize with the localized modes of individual nanostructures, producing sharp spectral features. According to ACS Nano, metal-insulator-metal sandwich nanodisks in periodic arrays create narrow, high-resonance peaks through radiation mode hybridization with Wood’s anomaly, generating vivid colors in both reflection and transmission.

    Mie-resonant metaphotonics Image: opg.optica.org - Mie-resonant metaphotonics

    The broader field of Mie-resonant metaphotonics, as reviewed in Advances in Optics and Photonics, examines how electric and magnetic multipoles govern light interaction in engineered structures, including the first and second Kerker conditions.

    Nonlinear Dimension

    What makes this particular result “dramatic and elusive” is that the Kerker-type interference is observed in the nonlinear response of the lattice. Nonlinear metasurfaces have been studied for second-harmonic generation and beam shaping. Work published in ACS Photonics demonstrated nonlinear beam shaping with plasmonic split-ring resonators, controlling second-harmonic wavefronts through local phase and amplitude manipulation. A more recent study in Nano Letters showed hybrid nonlinear metasurface lenses that generate and focus second-harmonic light.

    Hybrid Nonlinear Metasurface Refractive Lens Image: acs.org - Hybrid Nonlinear Metasurface Refractive Lens

    Extending the lattice Kerker condition into the nonlinear regime is harder because the nonlinear polarization sources are weaker, spectrally shifted, and subject to different symmetry constraints than their linear counterparts. The paper published in Wiley’s Nanophotonics journal reports success in observing this effect experimentally.

    Further Reading

    The primary paper is available at Wiley Online Library and provides the full experimental and theoretical treatment. For broader context on Mie resonances and Kerker conditions in metaphotonics, the review in Advances in Optics and Photonics offers a comprehensive multipolar analysis.

    Sources: Wiley Online Library, ACS Nano, Optica, ACS Photonics, Nano Letters