title: Identification of Plasmonic Modes in Parabolic Cylinder Geometry by Quasi-Separation of Variables.
abstract: This paper describes the plasmonic modes in the parabolic cylinder geometry as a theoretical complement to the previous paper (J Phys A 42:185401) that considered the modes in the circular paraboloidal geometry. In order to identify the plasmonic modes in the parabolic cylinder geometry, analytic solutions for surface plasmon polaritons are examined by solving the wave equation for the magnetic field in parabolic cylindrical coordinates using quasi-separation of variables in combination with perturbation methods. The examination of the zeroth-order perturbation equations showed that solutions cannot exist for the parabolic metal wedge but can be obtained for the parabolic metal groove as standing wave solutions indicated by the even and odd symmetries.
authors.affiliation: Department of Physics, Faculty of Education and Regional Studies, University of Fukui, Fukui, 910-8507 Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kurihara
authors.affiliation: Kobe Advanced ICT Research Center, National Institute of Information and Communications Technology (NICT), Kobe, 651-2492 Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Otomo
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, 816-8580 Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Graduate School of Engineering, Osaka University, 1-2 Yamadaoka, Suita, Osaka 565-0871 Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Takahara
authors.affiliation: Research Center for Development of Far-Infrared Region, University of Fukui, Fukui, 910-8507 Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tani
authors.affiliation: Department of Electrical, Electronics and Computer Engineering, Fukui University of Technology, Fukui, 910-8505 Japan.
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Kuwashima
keywords: Nanofocusing; Parabolic cylinder; Plasmonics; Quasi-separation of variables; Superfocusing; Surface plasmon polaritons