title: Design of ultrathin plasmonic quarter-wave plate based on period coupling.
abstract: Based on an analysis of the surface admittance of a plasmonic film with a substrate, we propose an ultrathin quarter-wave plate consisting of a periodic plane array of symmetrical L-shaped plasmonic antennas. The period, which determines the coupling among L-shaped antennas, is an important parameter for optimizing the performance of the structure. Numerical simulation results show that an Au quarter-wave plate designed in this Letter can efficiently convert a linearly polarized light at normal incidence into circularly polarized light, whose ellipticity is 0.994 at an operating wavelength of 1550 nm. The thickness is only 30 nm, which is nearly 1/50 of the wavelength of incident light.
authors: College of Opto-Electronic Engineering, National University of Defense Technology, Changsha 410073, China.
authors: Biao
authors: B
authors: Yang
authors: Wei-Min
authors: WM
authors: Ye
authors: Xiao-Dong
authors: XD
authors: Yuan
authors: Zhi-Hong
authors: ZH
authors: Zhu
authors: Chun
authors: C
authors: Zeng