Rotational Doppler shift induced by spin-orbit coupling of light at spinning metasurfaces
Rotational Doppler shift induced by spin-orbit coupling of light at spinning metasurfaces
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DOI：
10.1364/optica.4.001000
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发表时间：
2017-08-20
期刊：
影响因子：
10.4
通讯作者：
Zentgraf, Thomas
中科院分区：
文献类型：
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作者：
Georgi, Philip;Schlickriede, Christian;Zentgraf, Thomas
光与旋转物体的相互作用可以导致作为转移角动量的结果的频率偏移。光学表面上的亚波长等离子体纳米结构为局部光操纵提供了有效的平台，因此可以用于这种动量交换。在这里，我们展示了基于几何Pancharatnam-Berry相的反射型等离子体元表面q板，它们能够改变光的自旋和轨道角动量。当这些超颖表面以恒定的角速度旋转时，我们观察到反射光的旋转多普勒频移，这取决于总的角动量转移。超颖表面设计的灵活性甚至能够实现复杂的反射相位掩模，其可以同时将不同的轨道角动量传递到光束。我们的实验表明，这种复杂的超颖表面相位掩模可以用来获得空间变化的多普勒频移的反射光束轮廓。(C)2017美国光学学会
The interaction of light with spinning objects can lead to a frequency shift as a result of the transferred angular momentum. Subwavelength plasmonic nanostructures on an optical surface provide an efficient platform for local light manipulation and thus can be utilized for such momentum exchanges. Here we demonstrate reflective-type plasmonic metasurface q-plates based on the geometric Pancharatnam-Berry phase that are capable of changing the spin and orbital angular momentum of light. When these metasurfaces rotate at a constant angular speed, we observe a rotational Doppler frequency shift of the reflected light, which depends on the total angular momentum transfer. The flexibility in the design of the metasurfaces even enables complex reflective phase masks that can transfer different orbital angular momenta, at the same time, to the beam. Our experiments show that such complex metasurface phase masks can be used to obtain spatially variant Doppler shift in the reflected beam profile. (C) 2017 Optical Society of America