High-Efficiency Broadband Cross Polarization Converter for Near-Infrared Light Based on Anisotropic Plasmonic Meta-surfaces

We show that the linear polarization state of electromagnetic waves at near-infrared frequencies can be efficiently rotated to its orthogonal direction by an alternative design of anisotropic plasmonic meta-surfaces. Numerical results demonstrate that the reflection coefficient converting to cross polarization after reflection can be as high as ~96 % with a half-powered bandwidth ~40 % at the wavelength ~1.5 μm. The designed system is much thinner than conventional geometric-optics devices and does suffer little energy loss. The energy loss is ~10 % at the designed wavelength due to the Ohmic loss within the metals.