Department of Electrical Engineering, University of Washington, Seattle, WA 98195, USA.
Department of Physics, University of Washington, Seattle, WA 98195, USA.
Sci Adv. 2018 Feb 9;4(2):eaar2114. doi: 10.1126/sciadv.aar2114. eCollection 2018 Feb.
Conventional imaging systems comprise large and expensive optical components that successively mitigate aberrations. Metasurface optics offers a route to miniaturize imaging systems by replacing bulky components with flat and compact implementations. The diffractive nature of these devices, however, induces severe chromatic aberrations, and current multiwavelength and narrowband achromatic metasurfaces cannot support full visible spectrum imaging (400 to 700 nm). We combine principles of both computational imaging and metasurface optics to build a system with a single metalens of numerical aperture ~0.45, which generates in-focus images under white light illumination. Our metalens exhibits a spectrally invariant point spread function that enables computational reconstruction of captured images with a single digital filter. This work connects computational imaging and metasurface optics and demonstrates the capabilities of combining these disciplines by simultaneously reducing aberrations and downsizing imaging systems using simpler optics.
传统成像系统包含大型且昂贵的光学元件，这些元件可以依次减轻像差。超表面光学通过用平板和紧凑的器件替代庞大的组件，为小型化成像系统提供了一种途径。然而，这些器件的衍射性质会导致严重的色差，目前的多波长和窄带消色差超表面无法支持全可见光谱成像（400 到 700nm）。我们结合计算成像和超表面光学的原理，构建了一个具有数值孔径约为 0.45 的单个金属透镜的系统，该系统在白光照明下可生成清晰聚焦的图像。我们的金属透镜具有光谱不变的点扩散函数，可通过单个数字滤波器对捕获的图像进行计算重建。这项工作将计算成像和超表面光学联系起来，并展示了通过使用更简单的光学器件同时减少像差和缩小成像系统的能力，结合这两个学科的能力。
