Wide-angle 90°-polarization rotator using chiral metamaterial with negative refractive index

Abstract

We present a novel planar chiral metamaterial (CMM) that can realize the intriguing phenomenon of 90°-polarization rotation to the electromagnetic wave incidence with a linear polarization. This CMM consists of fourfold-symmetrically conjugated metallic pairs, which exhibits a circular dichroism and a giant optical activity. The fascinating 90°-polarization rotation of electromagnetic wave for a wide angle of incidence is demonstrated by both simulations and experiments. To be specific, the rotation angle per wavelength in our design is as large as 3400°/λ, implying that the chirality is significantly stronger than any other planar CMMs reported previously. Due to the giant chirality, the negative refractive index is achieved for circularly polarized waves.

Acknowledgements

This work was partially supported by the National Natural Science Foundation of China (Grant Nos. 50872113, 50936002) and the Northwestern Polytechnical University Foundation for Basic Research (Grant No. JC201154). W. Zhu also gratefully acknowledges the Australian Research Council for financial support within the frame of the Discovery Grant scheme under grant DP110100713.