发表机构
Sichuan Province Key Laboratory of Optoelectronic Sensor Devices and Systems, College of Optoelectronic Engineering (Chengdu IC Valley Industrial College), Chengdu University of Information Technology; Sichuan Meteorological Optoelectronic Sensor Technology and Application Engineering Research Center, Chengdu University of Information Technology; School of Precision Instruments and Opto-Electronics Engineering, Tianjin University（成都信息工程大学光电工程学院（成都IC谷产业学院）; 成都信息工程大学四川省气象光电传感器技术与应用工程研究中心; 天津大学精密仪器与光电子工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种基于外在手性的透射式全介质太赫兹超表面，实现自旋复用的图像边缘检测，在0.69太赫兹下右旋圆偏振入射时边缘增强，左旋时明场成像，有效数值孔径约0.4。
AI 中文摘要
外在手性超表面可以在不具有内在手性的平面结构中表现出显著的手性响应，这使得它们对于自旋选择性光操控具有吸引力。在此，我们提出了一种透射式全介质太赫兹超表面用于图像边缘检测。由于外在手性响应，该超表面在0.69太赫兹附近的右旋圆偏振入射下能够实现边缘增强成像，而在左旋圆偏振入射下则保持明场成像。空间频率分析表明，该器件的有效数值孔径约为0.4，表明太赫兹图像边缘检测可以在宽空间频率范围内实现。这项工作为具有自旋选择性和大数值孔径的透射式太赫兹全光图像处理提供了一条新的设计途径。
英文摘要
Extrinsically chiral metasurfaces can exhibit pronounced chiral responses in planar structures without intrinsic chirality, making them attractive for spin-selective light manipulation. Here, we propose a transmissive all-dielectric terahertz metasurface for image edge detection. Owing to the extrinsic chiral response, the metasurface enables edge-enhanced imaging under right-handed circularly polarized incidence near 0.69 THz, while preserving bright-field imaging under left-handed circularly polarized incidence. Spatial-frequency analysis shows that the effective numerical aperture of the device is approximately 0.4, indicating the terahertz image edge detection can be achieved over a broad spatial-frequency range. This work provides a new design route toward transmissive terahertz all-optical image processing with spin selectivity and a large numerical aperture.
