Manipulating broadband polarization conversion in metamaterials.

In this work, we investigate a hybrid metamaterial consisting of square split wires and cut-wires on a dielectric substrate. The metamaterial can exhibit a broadband cross-polarization conversion for both reflected and transmitted waves in the frequency range of about 10 GHz. We can coherently modulate the broadband linear and circular polarization conversions in the standing wave formed by two counterpropagating coherent beams. At electric antinodes and nodes, the metamaterial undergoes enhanced or vanishing polarization conversion due to interferometric effect. In particular, the broadband polarization conversion can be freely applied to different polarized waves and its efficiency can be easily accomplished via phase modulation between two input beams. The coherent control scheme enables the metamaterial to achieve a dynamic broadband modulation of the polarization state and is of importance for all-optical data processing and polarization crosstalk elimination. [ABSTRACT FROM AUTHOR]