90° polarization rotator using a bilayered chiral metamaterial with giant optical activity

A bilayered chiral metamaterial is proposed to realize a 90 degrees polarization rotator, whose giant optical activity is due to the transverse magnetic dipole coupling among the metallic wire pairs of enantiomeric patterns. By transmission through this thin bilayered structure of less than lambda/30 thick, a linearly polarized wave is converted to its cross polarization with a resonant polarization conversion efficiency of over 90%. It is demonstrated that the chirality in the propagation direction makes this efficient cross-polarization conversion possible. (C) 2010 American Institute of Physics. [doi:10.1063/1.3429683]