Kim Sun Il, Park Junghyun, Jeong Byung Gil, Lee Duhyun, Yang Ki-Yeon, Park Yong-Young, Ha Kyoungho, Choo Hyuck
Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, Republic of Korea.
Nanophotonics. 2022 Feb 2;11(11):2719-2726. doi: 10.1515/nanoph-2021-0664. eCollection 2022 Jun.
Tunable metasurfaces can change the optical properties of incident light at will such as amplitude, phase, and polarization in a time-dependent fashion. Ultrafast switching speed and the ability for the pixel size reduction of the tunable metasurface can allow various applications such as light detection and ranging, interferometric sensors, and free space optical communications, to name a few. Although there have been successful demonstrations of the wavefront shaping using the tunable metasurface, the implementation of the two-dimensional metasurface pixel array that can be individually addressed in the optical frequency regime still remains challenging. Here, we present the of the two-dimensional beam steering with the metasurface array by the binary phase grating in the infrared regime. The metasurface unit cell is composed of metal-dielectric-oxide structure with the indium tin oxide as an active layer, which is modulated by using the top fan-out electrodes. The metasurface array is two-dimensionally pixelated and has the phase change above 137° in the infrared regime.
可调谐超表面可以以时间相关的方式随意改变入射光的光学特性，如振幅、相位和偏振。超快的切换速度以及可调谐超表面减小像素尺寸的能力使得它能够应用于多种领域，比如光探测与测距、干涉式传感器以及自由空间光通信等等。尽管已经有利用可调谐超表面进行波前整形的成功演示，但在光频范围内能够单独寻址的二维超表面像素阵列的实现仍然具有挑战性。在此，我们展示了在红外波段利用二元相位光栅通过超表面阵列实现二维光束转向。超表面单元由金属-电介质-氧化物结构组成，其中氧化铟锡作为有源层，通过顶部扇出电极进行调制。该超表面阵列在二维上进行了像素化，并且在红外波段具有超过137°的相位变化。
