plasmonic wavelength demultiplexer with mode conversion capabilities

An efficient wavelength demultiplexer with its input as a metal-insulator-metal (mim) waveguide mode and output an out of plane free-space mode is proposed. the proposed demultiplexer design is integrated on a mim waveguide such that power is evanescently coupled into an array of appropriately designed cavity-groove combination. the demultiplexer design permits control of phase of the dropped wavelength to achieve a desired wavefront. we demonstrate this through generation of circular and plane wavefront. by controlling the evanescently coupled power into the cavity-groove combinations, it is possible to dramatically improve the efficiency of the proposed demultiplexer. results are simulated using fem technique.