Ji Jitao, Li Jian, Wang Zhizhang, Li Xueyun, Sun Jiacheng, Wang Junyi, Fang Bin, Chen Chen, Ye Xin, Zhu Shining, Li Tao
National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulations, College of Engineering and Applied Sciences, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing, 210093, China.
Nat Commun. 2024 Sep 27;15(1):8271. doi: 10.1038/s41467-024-52476-2.
On-chip metasurface for guided wave radiation works as an upgrade of conventional grating couplers, enriching the interconnection between guided wave and free-space optical field. However, the number of controllable parameters in equivalent Jones matrix of on-chip metasurface is limited that restricts the channels for multiplexing. Here, a supercell design based on detour phase and geometric phase has been proposed to reach full-parametric modulation of Jones matrix. As proof of concept, four independent sets of amplitude-phase channels have been experimentally demonstrated through a single on-chip metasurface. Moreover, through joint modulation of three phase mechanisms including detour phase, geometric phase and propagation phase, the Jones matrix could be decoupled from forward- and backward-propagating guided waves for direction multiplexing. This work paves the way for guided wave radiation towards high-capacity multiplexing and may further extend its application in optical communications, optical displays and augmented/virtual reality.
用于导波辐射的片上超表面作为传统光栅耦合器的升级版，丰富了导波与自由空间光场之间的互连。然而，片上超表面等效琼斯矩阵中可控参数的数量有限，这限制了复用通道。在此，提出了一种基于迂回相位和几何相位的超单元设计，以实现琼斯矩阵的全参数调制。作为概念验证，通过单个片上超表面实验演示了四组独立的幅度-相位通道。此外，通过对迂回相位、几何相位和传播相位这三种相位机制的联合调制，琼斯矩阵可以与向前和向后传播的导波解耦，以实现方向复用。这项工作为导波辐射向高容量复用铺平了道路，并可能进一步扩展其在光通信、光学显示和增强/虚拟现实中的应用。
