State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China.
Opt Lett. 2012 Dec 1;37(23):4940-2. doi: 10.1364/OL.37.004940.
We show that a flat metasurface with a parabolic reflection-phase distribution can focus an impinging plane wave to a point image in reflection geometry. Our system is much thinner than conventional geometric-optics devices and does not suffer the energy-loss issues encountered by many metamaterial devices working in transmission geometry. We designed realistic microwave samples and performed near-field scanning experiments to verify the focusing effect. Experimental results are in good agreement with full wave simulations, model calculations, and theoretical analyses.
我们展示了一种具有抛物线反射相位分布的平面超表面，它可以将入射的平面波在反射几何中聚焦到一个点像。我们的系统比传统的几何光学器件薄得多，并且不会像许多在传输几何中工作的超材料器件那样遇到能量损耗问题。我们设计了现实的微波样品，并进行了近场扫描实验来验证聚焦效果。实验结果与全波模拟、模型计算和理论分析吻合较好。
