Gold, silver, platinum and palladium typically crystallize with the face-centred cubic structure. Here we report the high-yield solution synthesis of gold nanoribbons in the 4H hexagonal polytype, a previously unreported metastable phase of gold. These gold nanoribbons undergo a phase transition from the original 4H hexagonal to face-centred cubic structure… (More)
High performance of a ring resonator and add-drop multiplexer with extremely small ring radius (1 or 2 μm) and a sub-wavelength confinement area of λ<sup>2</sup>/1200 is reported. It has been achieved using the silicon-based hybrid dielectric-loaded plasmonic waveguide approach.