On-Chip Photonic Spin Hall Lens
On-Chip Photonic Spin Hall Lens
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片上光子自旋霍尔透镜
DOI：
10.1021/acsphotonics.9b00551
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发表时间：
2019-08-01
期刊：
影响因子：
7
通讯作者：
Yuan, Xiaocong
中科院分区：
文献类型：
--
作者：
Du, Luping;Xie, Zhenwei;Yuan, Xiaocong
聚焦和傅里叶变换是光学镜头的两个关键功能，对于光学信息的提炼和处理至关重要。这些独特的功能持续存在，甚至在表面波上工作的平面配置上得以延续，从而实现片上超快光子信息处理。在这里，我们设计并演示了一种适用于表面等离子体激元的光子自旋霍尔透镜（pSHL）。它可以执行由入射圆偏振光（CPL）旋向控制的空间分离聚焦和光子傅里叶变换。通过改变编码到透镜上的相位梯度的比例因子（光学自旋霍尔效应的表现），可以轻松调整它们的分光距离。 pSHL 旨在检索补偿镜头空间移位所需的相位延迟；这是通过使用产生自旋依赖性 Pancharatnam-Berry 相的等离子体超表面来实现的。演示了 pSHL 在光子自旋路由和 OAM 模式解复用方面的应用。所提出的 pSHL 超薄、紧凑且易于制造。它为超紧凑光子自旋器件的开发带来了巨大的希望。
Focusing and Fourier transformation are two key functionalities of optical lenses, which are vital for optical information refining and processing. These unique features persist and are even carried forward on a planar configuration that works on a surface wave, enabling on-chip and ultrafast photonic information processing. Here, we design and demonstrate a type of photonic spin Hall lens (pSHL) that works on surface plasmon polaritons. It could perform spatially separated focusing and photonic Fourier transformation controlled by the handedness of the incident circularly polarized light (CPL). Their splitting distance can easily be adjusted by altering the scaling factor of the phase gradient encoded onto the lens, a manifestation of an optical spin Hall effect. The pSHL is designed to retrieve the phase delay required to compensate for the spatial shift of the lens; this is realized using a plasmonic metasurface that yields the spin-dependent Pancharatnam-Berry phases. Applications with the pSHL for photonic spin routing and OAM-mode demultiplexing are demonstrated. The proposed pSHL is ultrathin, compact, and easy to fabricate. It holds a great promise for the development of ultracompact photonic spin devices.