Manipulating optical signals at sub-wavelength scale by planar arrays of   metallic nanospheres: Towards plasmonic interference devices
  We show that interference can be the principle of operation of an all-optical switch and other nanoscale plasmonic interference devices (PIDs). The optical response of two types of planar plasmonic waveguides is studied theoretically: bent chains and Y-shaped configurations of closely-spaced metallic nanospheres. We study symmetric Y-shape arrays as an example of an all-optical switch and demonstrate that effective phase- and amplitude-sensitive control of the output signal can be achieved due to interference effects. 
A. V. Malyshev, V. A. Malyshev, and J. Knoester
cond-mat.mes-hall cond-mat.mtrl-sci physics.optics