Metascreen-based superdirective antenna in the optical frequency regime.
A metascreen designed to achieve near-field subwavelength focusing at a given frequency is shown to operate as a superdirective antenna in the vicinity of that frequency at the far field. A metascreen for microwave frequencies based on a simple perfect electrically conducting screen is initially used to explain the principle of operation as a superdirective antenna and to distinguish this operation mode from that resulting in near-field subwavelength focusing. A similar metascreen design based on a silver screen of a finite thickness is then used to demonstrate superdirectivity with nanoantennas in the optical frequency regime.
The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 40 St. George Street, Toronto, Ontario M5S 2E4, Canada. ludwiga@waves.utoronto.ca
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Eleftheriades