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EnglishIn this work, we employ scanning near-field optical microscopy, full-vector finite difference time domain numerical simulations and fractional Fourier transformation to investigate the near-field and propagation behavior of the electromagnetic energy scattered at 1.56μm by dielectric arrays of silicon nitride nanopillars with chiral 1-Vogel spiral geometry. In particular, we experimentally study the spatial evolution of scattered radiation and demonstrate near-field coupling between adjacent nanopillars along the parastichies arms. Moreover, by measuring the spatial distribution of the scattered radiation at different heights from the array plane, we demonstrate a characteristic rotation of the scattered field pattern consistent with net transfer of orbital angular momentum in the Fresnel zone, within a few micrometers from the plane of the array. Our experimental results agree with the simulations we performed and may be of interest to nanophotonics applications.
| Titolo: | Near-field distribution and propagation of scattering resonances in Vogel spiral arrays of dielectric nanopillars | |
| Autori di Ateneo: | ||
| Autori: | INTONTI, FRANCESCA; CASELLI, NICCOLO'; N. Lawrence; J. Trevino; WIERSMA, DIEDERIK SYBOLT; L. D. Negro | |
| Anno di registrazione: | 2013 | |
| Rivista: | ||
| Volume: | 15 | |
| Pagina iniziale: | 085023 | |
| Pagina finale: | 085028 | |
| Abstract: | In this work, we employ scanning near-field optical microscopy, full-vector finite difference time domain numerical simulations and fractional Fourier transformation to investigate the near-field and propagation behavior of the electromagnetic energy scattered at 1.56μm by dielectric arrays of silicon nitride nanopillars with chiral 1-Vogel spiral geometry. In particular, we experimentally study the spatial evolution of scattered radiation and demonstrate near-field coupling between adjacent nanopillars along the parastichies arms. Moreover, by measuring the spatial distribution of the scattered radiation at different heights from the array plane, we demonstrate a characteristic rotation of the scattered field pattern consistent with net transfer of orbital angular momentum in the Fresnel zone, within a few micrometers from the plane of the array. Our experimental results agree with the simulations we performed and may be of interest to nanophotonics applications. | |
| Handle: | http://hdl.handle.net/2158/864312 | |
| Appare nelle tipologie: | 1a - Articolo su rivista |
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