Integrated Wide-Band Power Divider/Combiner at Plasmonic Interfaces

We propose a wide-band power divider/combiner configuration to facilitate light access and manipulation in planar nano-plasmonic devices. Light is incident from a standard silicon nanowire (negligible propagation losses) to be accessed by a nano-plasmonic circuit providing subwavelength confinement. The structure circumvents the inherent losses associated with long distance light propagation in nano-plasmonic splitters as coupling and splitting are performed at the same interface with small splitting losses. Plasmonic slot waveguides (PSWs) are utilized for subwavelength confinement. Two PSWs placed orthogonally to a silicon nanowire are utilized for the power division/combining functionality. The power splitter has been analyzed by the finite-difference time-domain numerical method. The proposed device is of compact size and wide-band operation. The relative displacement of the silicon nanowire from the PSWs is optimized. A splitting of 34%, over most of the wavelength spectrum from 0.8-2.5 μm , is demonstrated.