Metasurface optics have demonstrated vast potential for implementing traditional optical components in an ultra-compact and lightweight form factor. Metasurface lenses, also called metalenses, however, suffer from severe chromatic aberrations, posing serious limitations on their practical use. Existing approaches for circumventing such aberrations via dispersion engineering are limited to small apertures and often entails multiple scatterers per unit cell with small feature sizes. Here, we present an alternative technique to mitigate chromatic aberration and demonstrate high-quality, full-color imaging using extended depth of focus (EDOF) metalenses and computational reconstruction. Previous EDOF metalenses relied on cubic phase masks that induced asymmetric artifacts in images, whereas here we demonstrate the use of symmetric phase masks that can improve subsequent image quality, including logarithmic-aspherical, and shifted axicon masks. Our work will inspire further development in achromatic metalenses beyond dispersion engineering and open new research avenues on hybrid optical-digital metasurface systems.

中文翻译：

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用于消色差计算成像的扩展焦深超透镜设计与分析

超表面光学已经展示了在超紧凑和轻巧的外形中实现传统光学组件的巨大潜力。然而，超表面透镜，也称为超透镜，存在严重的色差，严重限制了它们的实际应用。通过色散工程规避此类像差的现有方法仅限于小孔径，并且通常需要每个单位单元有多个具有小特征尺寸的散射体。在这里，我们提出了一种替代技术来减轻色差并展示使用扩展焦深 (EDOF) 超透镜和计算重建的高质量全彩色成像。以前的 EDOF 超透镜依赖于在图像中引起不对称伪影的三次相位掩模，而在这里，我们演示了使用对称相位掩模可以提高后续图像质量，包括对数非球面掩模和移位轴棱锥掩模。我们的工作将激发除色散工程之外的消色差超透镜的进一步发展，并为混合光学数字超表面系统开辟新的研究途径。