title: Periodic dielectric bars assisted enhanced transmission and directional light emission from a single subwavelength slit.
abstract: The transmission from a single subwavelength slit in a metal film with periodic dielectric bars on its surfaces has been analyzed numerically by the finite-difference time-domain method. Results show that the role of the periodic dielectric bars is just the same as that of the periodic grooves directly on the surfaces. With the modulations of dielectric bars on the input and output surfaces of the metal film, light transmission through the subwavelength slit is enhanced extraordinarily and confined to directional emission. The CDEW model is employed to explain the mechanism of the transmission enhancement and directional emission caused by the periodic dielectric bars.
authors.forename: Zu-Bin
authors.initials: ZB
authors.lastname: Li
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Tian
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Zhou
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Zang
authors.forename: Chunping
authors.initials: C
authors.lastname: Zhang