Key Laboratory of In-Fiber Integrated Optics of Ministry of Education, College of Science, Harbin Engineering University, Harbin 150001, China.
SZU-NUS Collaborative Innovation Centre for Optoelectronic Science &Technology, and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen, China.
Sci Rep. 2016 Nov 22;6:37476. doi: 10.1038/srep37476.
Coherent light-matter interaction in ultrathin metamaterials has been demonstrated to dynamically modulate intensity, polarization and propagation direction of light. The gradient metasurface with a transverse phase variation usually exhibits an anomalous refracted beam of light dictated by so-called generalized Snell's law. However, less attention has been paid to coherent control of the metasurface with multiple anomalous refracted beams. Here we propose an ultrathin gradient metasurface with single trapezoid-shaped slot antenna as its building block that allows one normal and two deflected transmitted beams. It is numerically demonstrated that such metasurface with multiple scattering modes can be coherently controlled to modulate output intensities by changing the relative phase difference between two counterpropagating coherent beams. Each mode can be coherently switched on/off and two deflected anomalous beams can be synchronously dictated by the phase difference. The coherent control effect in the trapezoid-shaped slit metasurface will offer a promising opportunity for multichannel signals modulation, multichannel sensing and wave front shaping.
超材料中的相干光物质相互作用已被证明可以动态调制光的强度、偏振和传播方向。具有横向相位变化的梯度超表面通常表现出由所谓的广义斯涅尔定律决定的异常折射光束。然而，对于具有多个异常折射光束的超表面的相干控制，人们的关注较少。在这里，我们提出了一种由单个梯形缝隙天线作为其构建块的超薄梯度超表面，它允许一个正常和两个折射透射光束。数值结果表明，通过改变两个相反传播的相干光束之间的相对相位差，这种具有多个散射模式的超表面可以进行相干控制，以调制输出强度。每个模式都可以相干地开启/关闭，并且两个折射的异常光束可以通过相位差同步控制。梯形缝隙超表面中的相干控制效应将为多通道信号调制、多通道传感和波前整形提供有前景的机会。
