Zhou Junxiao, Qian Haoliang, Chen Ching-Fu, Chen Li, Liu Zhaowei
Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States.
Materials Science and Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States.
Nano Lett. 2021 Jan 13;21(1):330-336. doi: 10.1021/acs.nanolett.0c03723. Epub 2020 Dec 18.
Optical metasurfaces have emerged as promising candidates for multifunctional devices. Dynamically reconfigurable metasurfaces have been introduced by employing phase-change materials or by applying voltage, heat, or strain. While existing metasurfaces exhibit appealing properties, they do not express any significant nonlinear effects due to the negligible nonlinear responses from the typical materials used to build the metasurface. In this work, we propose and experimentally demonstrate one kind of Kerr metasurface that shows strong intensity-dependent responses. The Kerr metasurface is composed of a top layer of gold antennas, a dielectric spacer, and a ground layer of metallic quantum wells (MQWs). Because of the large Kerr nonlinearity supported by the MQWs, the effective optical properties of the MQWs can change from metallic to dielectric with increasing of the input intensity, leading to dramatic modifications of the metasurface responses. This opens up new routes for potential applications in the field of nonlinear optics.
光学超表面已成为多功能器件的有前途的候选者。通过使用相变材料或施加电压、热量或应变，已经引入了动态可重构超表面。虽然现有的超表面表现出吸引人的特性，但由于用于构建超表面的典型材料的非线性响应可忽略不计，它们没有表现出任何显著的非线性效应。在这项工作中，我们提出并通过实验证明了一种克尔超表面，它表现出强烈的强度依赖响应。克尔超表面由顶层的金天线、介电间隔层和金属量子阱（MQW）的接地层组成。由于MQW支持的大克尔非线性，随着输入强度的增加，MQW的有效光学特性可以从金属变为电介质，从而导致超表面响应的显著改变。这为非线性光学领域的潜在应用开辟了新途径。
