Hybrid Dielectric-Loaded Plasmonic Waveguide-Based Power Splitter and Ring Resonator: Compact Size and High Optical Performance for Nanophotonic Circuits

摘要

The key challenge of the plasmonic waveguide is to achieve simultaneously both the long propagation length and high confinement. The hybrid dielectric-loaded plasmonic waveguide consists of a SiO2 stripe sandwiched between a Si-nanowire and a silver film and thus promises as a best candidate to overcome this challenge. We propose to exploit this unique property of this structure to design different high-efficient silicon-based plasmonic components including waveguide, power splitter, and wavelength-selective ring resonator. As a result, the proposed power splitter with a waveguide cross section (λ 2/60) and a strong mode confinement area (~λ 2/240) features a low power transmission loss (0.4 dB) at the optimal arm length of 4 μm with respect to different separation distances of output arms. Moreover, we also demonstrate that a plasmonic ring resonator with a compact ring radius of 2 μm may achieve high optical performance such as high-extinction ratio of 30 dB, large free spectral range of 67 nm, and small bandwidth of 0.6 nm. These superior performances make them promising building blocks for integrated nanophotonic circuits.