Cavity-involved plasmonic metamaterial for optical polarization conversion

We experimentally demonstrate a plasmonic assisted Fabry-Perot cavity in a metal/insulator/metal trilayer structure with L-shaped hole arrays inside, which significantly contribute to the mechanism to realize a nearly complete polarization conversion (=0.93) in optical transmissions at near-infrared wavelength. This interesting property is found arising from an overlap of the cavity and plasmonic modes in two orthogonal polarization states. This discovered physics remarkably endows this plasmonic metamaterial with good optical performance and looser fabrication requirement, not only indicating practical applications but also providing fruitful inspirations in future nanophotonic designs. (C) 2010 American Institute of Physics. [doi:10.1063/1.3533912]