Abdollahramezani Sajjad, Hemmatyar Omid, Taghinejad Mohammad, Taghinejad Hossein, Kiarashinejad Yashar, Zandehshahvar Mohammadreza, Fan Tianren, Deshmukh Sanchit, Eftekhar Ali A, Cai Wenshan, Pop Eric, El-Sayed Mostafa A, Adibi Ali
School of Electrical and Computer Engineering, Georgia Institute of Technology, 778 Atlantic Drive NW, Atlanta, Georgia 30332-0250, United States.
Department of Electrical Engineering, Department of Materials Science and Engineering, Precourt Institute for Energy, Stanford University, Stanford, California 94305, United States.
Nano Lett. 2021 Feb 10;21(3):1238-1245. doi: 10.1021/acs.nanolett.0c03625. Epub 2021 Jan 22.
Efficient hybrid plasmonic-photonic metasurfaces that simultaneously take advantage of the potential of both pure metallic and all-dielectric nanoantennas are identified as an emerging technology in flat optics. Nevertheless, postfabrication tunable hybrid metasurfaces are still elusive. Here, we present a reconfigurable hybrid metasurface platform by incorporating the phase-change material GeSbTe (GST) into metal-dielectric meta-atoms for active and nonvolatile tuning of properties of light. We systematically design a reduced-dimension meta-atom, which selectively controls the hybrid plasmonic-photonic resonances of the metasurface via the dynamic change of optical constants of GST without compromising the scattering efficiency. As a proof-of-concept, we experimentally demonstrate two tunable metasurfaces that control the amplitude (with relative modulation depth as high as ≈80%) or phase (with tunability >230°) of incident light promising for high-contrast optical switching and efficient anomalous to specular beam deflection, respectively. Our findings further substantiate dynamic hybrid metasurfaces as compelling candidates for next-generation reprogrammable meta-optics.
同时利用纯金属和全介质纳米天线潜力的高效混合等离子体光子超表面被视为平板光学领域的一项新兴技术。然而，制造后可调节的混合超表面仍然难以实现。在此，我们通过将相变材料锗锑碲（GST）纳入金属-介质元原子，提出了一种可重构混合超表面平台，用于对光的特性进行主动和非易失性调节。我们系统地设计了一种低维元原子，它通过GST光学常数的动态变化来选择性地控制超表面的混合等离子体光子共振，而不影响散射效率。作为概念验证，我们通过实验展示了两种可调节超表面，分别用于控制入射光的振幅（相对调制深度高达≈80%）或相位（可调性>230°），有望分别用于高对比度光开关和高效的异常到镜面光束偏转。我们的研究结果进一步证实了动态混合超表面是下一代可重新编程元光学的有力候选者。
