Events Calendar
Metasurface-enhanced light emission
Wednesday March 21, 2018
| 11:00 am
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Presenter: | Dr. Roberto Paiella, Electrical and Computer Engineering & Photonics Center, Boston University |
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| Series: | OSE Seminars | |
| Abstract: | Metallic nanostructures can be used as optical antennas to control the radiation properties of nearby light emitters, via the near-field excitation and subsequent radiative decay of plasmonic oscillations. Here this basic idea is investigated as a means to increase the efficiency and functionality of optoelectronic light-emitting devices. Large enhancements in the radiative efficiency of III-nitride LED materials have been obtained through the use of localized surface-plasmon resonances and lattice surface modes in periodic arrays of metallic nanocylinders. Unidirectional beaming at geometrically tunable angles has also been demonstrated, based on the excitation of surface plasmon polaritons and their diffractive scattering by a phased array of asymmetric metallic nanoparticles. The latter approach is currently being generalized to the use of gradient metasurfaces (i.e., planar nanoantenna arrays designed to introduce a linearly graded phase shift upon reflection), which can provide remarkable flexibility in tailoring far-field radiation patterns. Finally, we are investigating the design of dielectric metasurfaces supporting strong Mie-resonant lattice surface modes, that can produce similarly large enhancements in spontaneous emission rates without the additional optical absorption losses of plasmonic systems. | |
| Location: | Room 101, Center for High Tech Materials | |
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