Open AccessBroadband unidirectional generation of surface plasmon polaritons with dielectric–film–coated asymmetric single–slit
Author(s) -
Jianjun Chen,
Zhi Li,
Ming Lei,
Song Yue,
Jinghua Xiao,
Qihuang Gong
Publication year - 2011
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.19.026463
Subject(s) - materials science , surface plasmon polariton , optics , transmittance , surface plasmon , dielectric , plasmon , optoelectronics , broadband , physics
A dielectric-film-coated asymmetric single nanoslit is proposed to realize broadband unidirectional generation of surface plasmon polaritons (SPPs). Due to the tight field confinements by the dielectric film and the deep groove in the asymmetric single slit, the transmittance of the SPPs in the groove to the left side considerably decreases. This greatly suppresses the left-propagating SPP generation efficiency for a broad bandwidth. Meanwhile, the right-propagating SPP generation efficiency has a flat spectra range because of the low transmittance, too. So the unidirectional SPP generation with bandwidth of >100 nm around λ = 750 nm is experimentally achieved for the device lateral dimension of only 865 nm.