Propagation characteristics of silver nanorods based compact waveguides for plasmonic circuitry

We propose ultra-compact waveguides for plasmonic circuitry based on silver nanorods array embedded vertically into silicon on insulator (SOI) substrate for nanoscale guidance of optical frequencies. Silver nanorods array palisade silicon to form core of SOI waveguide and is theoretically modeled for the first time. Propagation characteristics of the structure are obtained using finite difference time domain (FDTD) computations, exposing bandgap in the visible regime for transverse magnetic modes and are verified by the plane wave expansion (PWE) method. Narrow transmission bandwidth of ∼10 nm with quality factor and confinement factor of 97.5% and 92% is achieved respectively, confirming strong confinement of the propagating mode at 633 nm and the losses calculated in decible per micrometer (dB/μm) for the waveguide is found to be .75 dB/μm for straight waveguide. Further, Y-splitter designed from the basis equally bifurcate power and the outputs received at the two ends are in phase yielding a viable 50–50 power splitter. Bend design routing light in nano-dimensions is also implemented successfully, offering components for high density plasmonic circuitry.

Graphical abstractWe propose ultra-compact waveguides for plasmonic circuitry based on silver nanorods array embedded vertically into silicon on insulator substrate for nanoscale guidance of optical frequencies.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Silver nanorods based plasmonic waveguide is proposed. ► 3D FDTD and PWE methods are used for examining the basis waveguide. ► Proposed waveguide works for visible regime. ► Straight waveguide, bend and Y-splitter have been devised. ► Quality factor, confinement factor and losses are calculated.