Light Propagation with Phase Discontinuities: Generalized Laws of Reflection and Refraction
Light Propagation with Phase Discontinuities: Generalized Laws of Reflection and Refraction
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DOI：
10.1126/science.1210713
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发表时间：
2011-10-21
期刊：
影响因子：
56.9
通讯作者：
Gaburro, Zeno
中科院分区：
文献类型：
--
作者：
Yu, Nanfang;Genevet, Patrice;Gaburro, Zeno
传统的光学元件依靠在光传播过程中积累的逐渐相移来整形光束。通过在波长范围内引入突变的相变来获得新的自由度。具有空间变化的相位响应和亚波长分离的二维光学谐振器阵列可以在传播的光穿过两种介质之间的界面时在其上留下这种相位不连续的印记。在这种情况下，在沿界面呈线性相位变化的硅基光学薄阵金属天线中观察到了反常反射和折射现象，这与由费马原理导出的广义定律非常一致。位相不连续为光束的设计提供了极大的灵活性，通过使用平面设计的金属界面产生光学涡旋就是例证。
Conventional optical components rely on gradual phase shifts accumulated during light propagation to shape light beams. New degrees of freedom are attained by introducing abrupt phase changes over the scale of the wavelength. A two-dimensional array of optical resonators with spatially varying phase response and subwavelength separation can imprint such phase discontinuities on propagating light as it traverses the interface between two media. Anomalous reflection and refraction phenomena are observed in this regime in optically thin arrays of metallic antennas on silicon with a linear phase variation along the interface, which are in excellent agreement with generalized laws derived from Fermat's principle. Phase discontinuities provide great flexibility in the design of light beams, as illustrated by the generation of optical vortices through use of planar designer metallic interfaces.