Polarization dependence and independence of near-field enhancement through a subwavelength circle hole.
By setting a metal rod or tooth-type structures in a single subwavelength hole, its near-field can be strongly enhanced. The near-field enhancement has strong polarization dependence when the structure in hole is twofold symmetric. Only the polarization along the longitudinal side of the metal rod or tooth-type structure can lead to strongest enhancement, which is attributed to the resonance of the localized surface plasmon. However, if the structure in hole is fourfold symmetric, the near-field enhancement is free from the polarization.
Li
Zu-Bin
ZB
The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, Teda Applied Physics School, Nankai University, Tianjin 300457, China .
Zhou
Wen-Yuan
WY
Kong
Xiang-Tian
XT
Tian
Jian-Guo
JG
D003198:Computer Simulation; D008027:Light; D008962:Models, Theoretical; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*