Plasmonic metamaterial wave retarders in reflection by orthogonally oriented detuned electrical dipoles

We demonstrate that a pair of perpendicular electrical dipolar scatterers resonating at different frequencies can be used as a metamaterial unit cell to construct a nanometer-thin retarder in reflection, designing nanocross and nanobrick plasmonic configurations to function as reflecting quarter-wave plates at similar to 1520 and 770nm, respectively. The design is corroborated experimentally with a monolayer of gold nanobricks, transforming linearly polarized incident radiation into circularly polarized radiation at similar to 780nm. (C) 2011 Optical Society of America