School of Materials Science and Engineering, Georgia Institute of Technology , 771 Ferst Drive, Atlanta, Georgia 30332, United States.
Nano Lett. 2014 Feb 12;14(2):1021-5. doi: 10.1021/nl404572u. Epub 2014 Jan 15.
We demonstrate enormously strong chiral effects from a photonic metamaterial consisting of an array of dual-layer twisted-arcs with a total thickness of ∼ λ/6. Experimental results reveal a circular dichroism of ∼ 0.35 in the absolute value and a maximum polarization rotation of ∼ 305°/λ in a near-infrared wavelength region. A transmission of greater than 50% is achieved at the frequency where the polarization rotation peaks. Retrieved parameters from measured quantities further indicate an actual optical activity of 76° per λ and a difference of 0.42 in the indices of refraction for the two circularly polarized waves of opposite handedness.
我们展示了由双层扭曲弧形阵列组成的光子超材料所产生的极强手性效应，其总厚度约为 λ/6。实验结果表明，在近红外波长区域，圆二色性约为 0.35，最大偏振旋转约为 305°/λ。在偏振旋转峰值频率处，实现了大于 50%的透过率。从测量量中提取的参数进一步表明，实际的旋光性为每 λ 76°，并且两个手性相反的圆偏振光的折射率差值为 0.42。
