The prospect of controlling the interaction of light with matter at nanoscale has been widely studied in recent years, and entails characterizing optical and optoelectronic devices at resolution higher than the diffraction limit. One technique that allows localization of light to sub-wavelength dimensions is through the use of surface plasmon polaritons (SPPs) wherein the interaction of light with free electrons on a metal surface can lead to a bound surface electromagnetic field that is confined to deep sub-wavelength dimensions. Studies based on SPPs merged with the field of nanotechnology have resulted in novel imaging technologies, nonlinear and quantum-optical devices and the ability to design materials with unusual electromagnetic properties with potential applications ranging from enhancing the efficiency of photovoltaic devices to detection of bio-molecules at ultra-small concentrations.
Here we report the design of nanophotonic devices based on SPP waveguide structures that would act as a true counterpart to todayβs electronic devices, providing orders of increase in data speeds while maintaining nanoscale dimensions. The devices are based on metal-dielectric-metal (MDM) waveguide structures composed of Ag/SiO2/Ag heterostructure that utilizes interference effect within multiple intersecting plasmonic waveguides. We have explored guided-wave devices such as L and T-bends, 4-way-splitters and 2x2-networked structures, wherein by altering the device geometry one can tune its operating frequency, and by changing the angle of incidence one can switch these devices between ON/OFF states. We plan to fabricate and experimentally characterize these devices for applications in color routing, directional filters and optical switches. We discuss preliminary design rules and constraints based on results obtained from finite-difference-time-domain simulations
