Tunable Polarization States With Helical Metamaterials

In this letter, we demonstrate the relationship between the incident angles and the polarization states of transmitted beams on the basis of a kind of helical metamaterials. Through finite-difference time-domain simulations, it is found that the polarization states of the transmitted lights can be tuned by changing the incident angles. When the angles vary from 20^° to -20^°, the axial ratios of the transmitted lights have significant changes from 1:0.93 to 1:0.59. This phenomenon of the tunable polarization can be explained qualitatively through the analysis of the surface current on the helical wires.