Open AccessNear-field beam focusing by a single bare subwavelength metal slit with the high-index transmission space
Author(s) -
Yan Guo,
Bo Zhao,
Jianjun Yang
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.013949
Subject(s) - optics , slit , physics , refractive index , transmission (telecommunications) , extraordinary optical transmission , interference (communication) , beam (structure) , near and far field , near field optics , space (punctuation) , light beam , transmission coefficient , field (mathematics) , surface plasmon , plasmon , surface plasmon polariton , telecommunications , scanning electron microscope , channel (broadcasting) , mathematics , optical microscope , pure mathematics , linguistics , philosophy , computer science
We theoretically demonstrate that a single bare subwavelength metal slit without any surrounding corrugations can have a capability to steer the incident light into focusing patterns by introducing a high index in the transmission half-space. The focusing properties are identified to depend on both the slit width and the output permittivity. The underlying physics lies in the interference of quasi-cylindrical waves scattered from the slit, and our proposed model agrees well with the simulation results. This finding is believed to inspire some novel ideas for the nano-optics design.