Optical Magnetic Multipolar Resonances in Large Dynamic Metamolecules
| Autor: | Seung Beom Pyun, So Jung Park, Eun Chul Cho, Connor Woods, Sung Wook Kim, Omar Ibrahim, Sunghee Lee, Zahra Fakhraai |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
FOS: Physical sciences 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials 010309 optics General Energy 0103 physical sciences Physical and Theoretical Chemistry 0210 nano-technology Optics (physics.optics) Physics - Optics |
| Popis: | Dynamic metamolecules (DMMs) are composed of a dielectric core made of hydrogel surrounded by randomly-packed plasmonic beads that can display magnetic resonances when excited by light at optical frequencies. Their optical properties can be controlled by controlling their core diameter through temperature variations. We have recently shown that DMMs display strong optical magnetism, including magnetic dipole and magnetic quadrupole resonances, offering significant potential for novel applications. Here, we use a T-matrix approach to characterize the magnetic multipole resonance modes of model metamolecules and explore their presence in experimental data. We show that high-order multipole resonances become prominent as the bead size and the overall structure sizes are increased, and when the the inter-bead gap is decreased. In this limit, mode mixing among high-order magnetic multipole modes also become significant, particularly in the directional scattering spectra. We discuss trends in magnetic scattering observed in both experiments and simulations, and provide suggestions for experimental design and verification of high-order optical magnetic resonances in the forward or backward scattering spectra. In addition, angular scattering of higher-order magnetic modes can display Fano-like interference patterns that should be experimentally detectable. Revised version of paper: added references, rearranged content and improved discussions, added new figures, and improved existing figures |
| Databáze: | OpenAIRE |
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