Dynamic Focusing with High-Quality-Factor Metalenses
Dynamic Focusing with High-Quality-Factor Metalenses
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DOI：
10.1021/acs.nanolett.0c01359
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发表时间：
2020-07-08
期刊：
影响因子：
10.8
通讯作者：
Dionne, Jennifer A.
中科院分区：
文献类型：
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作者：
Klopfer, Elissa;Lawrence, Mark;Dionne, Jennifer A.
超表面透镜为聚焦光线提供了一个超薄的平台，但微弱的光与物质的相互作用限制了它们的动态可调性。在这里，我们设计了亚微米厚、超高品质因数(高Q)的金属透镜，能够动态调节焦距和强度。利用全场模拟，我们证明了通过在组成硅的纳米天线中包括微妙的周期性微扰，可以产生超过5000的品质因数。这种高Q共振实现了基于非线性克尔效应的透镜调制，焦距从4到6.5微米变化，随着输入光强从0.1增加到1毫瓦/微米(2)，焦强度降低了一半。我们还展示了如何通过适当的微扰位置将多个高Q共振嵌入到透镜响应中。我们的高Q透镜设计具有比现有透镜设计高2个数量级的品质因数，为可重构、多路复用和高光谱亚表面成像平台提供了基础。
Metasurface lenses provide an ultrathin platform in which to focus light, but weak light-matter interactions limit their dynamic tunability. Here we design submicron-thick, ultrahigh quality factor (high-Q) metalenses that enable dynamic modulation of the focal length and intensity. Using full-field simulations, we show that quality factors exceeding 5000 can be generated by including subtle, periodic perturbations within the constituent Si nanoantennas. Such high-Q resonances enable lens modulation based on the nonlinear Kerr effect, with focal lengths varying from 4 to 6.5 mu m and focal intensities decreasing by half as input intensity increases from 0.1 to 1 mW/mu m(2). We also show how multiple high-Q resonances can be embedded in the lens response through judicious placement of the perturbations. Our high-Q lens design, with quality factors 2 orders of magnitude higher than existing lens designs, provides a foundation for reconfigurable, multiplexed, and hyperspectral metasurface imaging platforms.