Design and optimization of a high-efficiency nanoscale ±90° light-bending structure by mode selection and tailoring

We tailor the dispersive properties of a nanoscale structure to enable +/- 90 degrees visible light-bending. The geometry and constituent materials of the structure are selected such that two low-loss modes are available to channel light toward and away from a nanoscale 90 degrees-bend. Based on numerical simulations of visible light propagation through the structure, we propose an optimized geometry that yields maximum field overlap between the mode propagating toward and the mode propagating away from the 90 degrees-bend, resulting in a peak bending efficiency of 92%. (C) 2010 American Institute of Physics. [doi:10.1063/1.3501130]