Chamoli Sandeep Kumar, Jin Chunqi, Fan Yandong, Kiani Mehdi, Goh Heedong, Huang Chen, Guo Shuyu, Wang Yuntong, Zhu Fei, Xing Guohua, Li Bo, Bai Tian, Alù Andrea, Li Wei
GPL Photonics Laboratory, State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jilin, 130033, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2025 May 14;16(1):4473. doi: 10.1038/s41467-025-59765-4.
All-optical image processing based on metasurfaces is a swiftly advancing field of technology, due to its high speed, large integrability and inherently low energy requirements. So far, the proposed devices have been focusing on canonical operations, such as differentiations to perform edge detection across all objects in a complex scene. Yet, undesired background noise and clutter can hinder such operations, requiring target selection with digital post-processing which inherently limits the overall accuracy, efficiency and speed. Here, we introduce an optical solution for real-time size-selective image processing and experimentally demonstrate the concept with a metal-dielectric-metal film performing a spatial band-pass filter in momentum space. We show high-resolution (~0.9 μm) edge detection and real-time dynamic denoising, ideally suited for bio-imaging applications and target recognitions. Our demonstrated k-space filtering metasurface expands the scope of nonlocal flat optics for analog image processing, ushering in opportunities for ultra-compact, cost-effective, and multifunctional image processors.
基于超表面的全光图像处理是一个迅速发展的技术领域，因其具有高速、高集成度以及固有的低能量需求。到目前为止，所提出的器件一直专注于典型操作，例如通过微分在复杂场景中的所有物体上执行边缘检测。然而，不需要的背景噪声和杂波会阻碍此类操作，需要通过数字后处理进行目标选择，这本质上限制了整体精度、效率和速度。在这里，我们介绍一种用于实时尺寸选择性图像处理的光学解决方案，并通过在动量空间中执行空间带通滤波器的金属 - 介质 - 金属薄膜对该概念进行了实验验证。我们展示了高分辨率（约0.9μm）的边缘检测和实时动态去噪功能，非常适合生物成像应用和目标识别。我们展示的k空间滤波超表面扩展了用于模拟图像处理的非局部平面光学的范围，为超紧凑、经济高效且多功能的图像处理器带来了机遇。
