【摘要】 在涡旋光束的实际应用中，拓扑荷的高精度检测具有重要意义。针对现有拓扑荷检测方法存在分辨率低、难以同时判别整数阶与分数阶拓扑荷的问题，本文从理论上提出了一种基于设计超表面的拓扑荷双重判别方法，并通过数值模拟进行验证。该超表面产生的内外衍射图样可分别用于判别拓扑荷的数值与符号，且所提方法的检测精度可达0.05。理论分析与仿真结果充分验证了该方法的有效性。该方法采用平面结构设计，无需额外光学元件，无需数据处理，检测精度高。此项工作有助于推动拓扑荷检测技术的发展及光学涡旋的实际应用。更多还原

【Abstract】 High-precision detection of topological charge is significant for the practical applications of vortex beams. In view of the existing evaluation with low resolution of topological charge and more complexity to judge simultaneously integer and fraction, this paper theoretically proposes and numerically verifies the double judgment method for topological charge based on the designed metasurface. The inner and outer diffraction patterns of metasurface can judge the value and sign of topological charge. The detection precision of the proposed method reaches 0.05. The theoretic and simulated results give the solid verification for the effectiveness of the proposed method. This method has outstanding advantages including planar structure design without additional elements, direct judgment without data processing and high precision over the existing methods, which is beneficial to the detection of topological charge and the applications of optical vortices.更多还原