Xiao Yongjiang, Liao Kun
Appl Opt. 2025 Jun 20;64(18):5106-5114. doi: 10.1364/AO.559786.
A dual-channel reconfigurable metasurface based on vanadium dioxide () and photosensitive silicon is proposed to realize offset focusing and holographic imaging. Based on the Pancharatnam-Berry (PB) phase principle, the three-bit quantization of the cross-reflection phase in the range of 360° is realized by rotating the in-plane mechanism of the unit. Based on the compensated phase formula, focusing theory, and Gerchberg-Saxton (GS) algorithm, the phase distributions of the metasurface are calculated, respectively. When phase change materials (PCMs) are both insulated, the array can achieve offset focusing in circular polarization. Broadband holographic imaging can be performed when both PCMs are in a metallic state. The metasurface's structure is simple, and its function is reconfigurable. The design has good potential for application in terahertz communication, imaging, and target detection. It provides a reference for the design of efficient, lightweight, and low-cost terahertz functional devices.
提出了一种基于二氧化钒（）和光敏硅的双通道可重构超表面，以实现偏置聚焦和全息成像。基于庞加莱-贝里（PB）相位原理，通过旋转单元的面内机构实现了360°范围内交叉反射相位的三位量化。基于补偿相位公式、聚焦理论和格奇伯格-萨克斯顿（GS）算法，分别计算了超表面的相位分布。当相变材料（PCM）均处于绝缘状态时，该阵列可在圆极化中实现偏置聚焦。当两个PCM均处于金属状态时，可进行宽带全息成像。该超表面结构简单，功能可重构。该设计在太赫兹通信、成像和目标检测方面具有良好的应用潜力。它为高效、轻质和低成本太赫兹功能器件的设计提供了参考。
