title: Polarization dependence and independence of near-field enhancement through a subwavelength circle hole.
abstract: 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.
authors.affiliation: The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, Teda Applied Physics School, Nankai University, Tianjin 300457, China .
authors.forename: Zu-Bin
authors.initials: ZB
authors.lastname: Li
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Zhou
authors.forename: Xiang-Tian
authors.initials: XT
authors.lastname: Kong
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Tian
mesh_terms: D003198:Computer Simulation; D008027:Light; D008962:Models, Theoretical; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*