Holographic detection of the orbital angular momentum of light with plasmonic photodiodes
Holographic detection of the orbital angular momentum of light with plasmonic photodiodes
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DOI：
10.1038/ncomms2293
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发表时间：
2012-12-01
影响因子：
16.6
通讯作者：
Capasso, Federico
中科院分区：
文献类型：
--
作者：
Genevet, Patrice;Lin, Jiao;Capasso, Federico
诸如等离子体光栅和等离子体透镜的金属部件通常用于将自由空间光束转换成传播的表面等离子体激元，反之亦然。这一代耦合器处理相对简单的光束，如平面波或高斯光束。在这里，我们提出了一个强大的概括这一战略更复杂的波前，如涡旋光束进行轨道角动量，也被称为拓扑电荷。这种方法是基于全息原理：耦合器被设计为入射涡旋光束和聚焦表面等离子体激元的干涉图案。我们已经将这些全息等离子体界面集成到商业硅光电二极管中，并证明这种设备可以选择性地检测光的轨道角动量。这种全息方法是非常普遍的，可以用来选择性地耦合自由空间光束到任何类型的表面波，如聚焦表面等离子体激元和等离子体艾里光束。
Metallic components such as plasmonic gratings and plasmonic lenses are routinely used to convert free-space beams into propagating surface plasmon polaritons and vice versa. This generation of couplers handles relatively simple light beams, such as plane waves or Gaussian beams. Here we present a powerful generalization of this strategy to more complex wave-fronts, such as vortex beams that carry orbital angular momentum, also known as topological charge. This approach is based on the principle of holography: the coupler is designed as the interference pattern of the incident vortex beam and focused surface plasmon polaritons. We have integrated these holographic plasmonic interfaces into commercial silicon photodiodes, and demonstrated that such devices can selectively detect the orbital angular momentum of light. This holographic approach is very general and can be used to selectively couple free-space beams into any type of surface wave, such as focused surface plasmon polaritons and plasmonic Airy beams.