title: Directional coupling in long-range dielectric-loaded plasmonic waveguides.
abstract: Directional couplers (DCs) based on long-range dielectric-loaded surface plasmon-polariton waveguides (LR-DLSPPWs) operating at telecom wavelengths are studied both numerically and experimentally. The investigated LR-DLSPPWs are formed by ~1.2-µm-high and 1-µm-wide polymer ridges fabricated atop of 15-nm-thick and 500-nm-wide gold stripes supported by a 288-nm-thick Ormoclear polymer deposited on a low-index (n(s) ≈1.34) layer of Cytop. DC structures consisting of sine-shaped S-bends (having an offset of ~10 µm over a distance of ~20 µm) and ~100-µm-long parallel LR-DLSPPWs with a center-to-center separation of 2 µm are characterized using scanning near-field microscopy. The experimentally obtained values of the propagation length (~400 µm), S-bend loss (~4 dB) and coupling length (~100 µm) are found in good agreement with the numerical simulations, indicating a significant potential of LR-DLSPPWs for the realization of various plasmonic components.
authors.affiliation: Department of Technology and Innovation, University of Southern Denmark, Niels Bohrs Allé 1, Odense, Denmark. zenin@iti.sdu.dk
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Zenin
authors.forename: Zhanghua
authors.initials: Z
authors.lastname: Han
authors.forename: Valentyn S
authors.initials: VS
authors.lastname: Volkov
authors.forename: Kristjan
authors.initials: K
authors.lastname: Leosson
authors.forename: Ilya P
authors.initials: IP
authors.lastname: Radko
authors.forename: Sergey I
authors.initials: SI
authors.lastname: Bozhevolnyi
mesh_terms: D017097:Electric Impedance; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*