Controlling propagation and coupling of waveguide modes using phase-gradient metasurfaces
Controlling propagation and coupling of waveguide modes using phase-gradient metasurfaces
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DOI：
10.1038/nnano.2017.50
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发表时间：
2017-07-01
影响因子：
38.3
通讯作者：
Yu, Nanfang
中科院分区：
文献类型：
--
作者：
Li, Zhaoyi;Kim, Myoung-Hwan;Yu, Nanfang
对二维设计光学结构或超表面的研究主要集中在控制光在自由空间中传播的波前。在这里，我们表明，梯度元表面结构组成的相控阵列的等离子体或介电纳米天线可以用来控制导波通过强光学散射在亚波长间隔。基于这一设计原理，我们在实验上演示了波导模式转换器、偏振旋转器和支持非对称光功率传输的波导器件。我们还展示了基于Mie谐振器相控阵的全介质片上偏振旋转器，其插入损耗可忽略不计。我们的梯度超颖表面可以实现小尺寸、宽带和低损耗的光子集成器件。
Research on two-dimensional designer optical structures, or metasurfaces, has mainly focused on controlling the wavefronts of light propagating in free space. Here, we show that gradient metasurface structures consisting of phased arrays of plasmonic or dielectric nanoantennas can be used to control guided waves via strong optical scattering at subwavelength intervals. Based on this design principle, we experimentally demonstrate waveguide mode converters, polarization rotators and waveguide devices supporting asymmetric optical power transmission. We also demonstrate all-dielectric on-chip polarization rotators based on phased arrays of Mie resonators with negligible insertion losses. Our gradient metasurfaces can enable small-footprint, broadband and low-loss photonic integrated devices.