全光控制非局域性用于激子超表面超快图像处理
All-Optical Control over Nonlocality for Ultrafast Image Processing with an Excitonic Metasurface
- University of Amsterdam（阿姆斯特丹大学）
- City University of New York（纽约市立大学）
- Politecnico di Milano（米兰理工大学）
- NWO-Institute AMOLF（荷兰皇家科学院AMOLF研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过将介电非局域超表面与多层WS2集成，利用激子共振实现全光超快边缘检测与明场成像切换，为自适应光学计算提供可重构平台。
AI中文摘要：
图像处理是许多现代技术（如增强现实和自动驾驶）的基础，然而传统的数字方法仍然能耗高且速度受限。非局域超表面——在纳米尺度上设计的二维结构，支持离域化、色散工程化的共振——提供了一种快速、节能且超薄的平台，可直接在光路上进行图像处理。在该平台中引入可调性是一项突出的挑战，这将实现对所实施处理操作的动态实时控制，促进其灵活集成到自适应和多功能光子架构中。在此，我们通过将介电非局域超表面与多层WS2集成，展示了超快速度下的光学可调边缘检测，WS2的强激子驱动光学响应使得能够以亚皮秒速度动态控制超表面的非局域性。利用WS2中A激子的共振光学泵浦，通过调整其空间非局域性，超表面的传递函数可快速从边缘检测切换到明场成像。该器件在可见光谱范围（波长约700 nm）内工作，展现出超快切换时间，并对法向入射光达到11.5 dB的振幅调制深度。该方法为自适应光学计算系统提供了一个可重构、超薄、全光平台，并突显了二维材料的高非线性特性在超快速度下有源超表面中的潜力。
英文摘要：
Image processing lies at the foundation of many modern technologies, such as augmented reality and autonomous driving, yet conventional digital approaches remain energy-intensive and limited in speed. Nonlocal metasurfaces - 2D structures engineered at the nanoscale to support delocalized, dispersion engineered resonances - provide a fast, energy-efficient and ultrathin platform to perform image processing directly on the light path. Introducing tunability in this platform is an outstanding challenge, and would enable dynamic real-time control over the implemented processing operation, facilitating flexible integration into adaptive and multifunctional photonic architectures. Here, we demonstrate optically tunable edge detection at ultrafast speeds by integrating a dielectric nonlocal metasurface with multilayer WS2, whose strong exciton-driven optical response enables dynamic control of the metasurface nonlocality at sub-ps speeds. Using resonant optical pumping of the A-exciton in WS2, the metasurface transfer function is rapidly switched from edge detection to bright-field imaging by tuning its spatial nonlocality. Operating in the visible spectral range at a wavelength around 700 nm, the device shows ultrafast switching times and reaches an amplitude modulation depth of 11.5 dB for normal incident light. This approach provides a reconfigurable, ultrathin, all-optical platform for adaptive optical computing systems and highlights the potential of the highly nonlinear properties of 2D materials for active metasurfaces at ultrafast speeds.
