Simulations of nanoscale interferometer and array focusing by metal heterowaveguides

We propose a three-dimensional (3D) nanoscale metal heterowaveguide for nanoguiding of light in nanometric cross section. Finite-difference time-domain simulation reveals that a light beam with 35nmx55nm cross section can effectively propagate along the heterowaveguides with 2.84dB/mum energy loss. 3D nanoscale Mach-Zehnder interferometers and metal waveguide arrays constructed by such heterowaveguides show interesting sensing and array nanofocusing properties, implying potential applications in the fields of nanophotonics such as nanosensing, nanolithography, array imaging, and controlling of the flow of light etc.