Surface that perceives depth: 3D imaging with metasurfaces

<正>When Galileo Galilei (1564-1642) was building his super bulky lenses for telescopes, he could not imagine that 400 years later, metasurfaces,which are hundred times thinner than a human hair,1–3could reproduce the function of his lenses. Indeed, for a few centuries, conventional bulky optics, such as lenses, prisms, mirrors, etc., have been the only tools for shaping the wave-front of light via engineering the optical path of light beams through media of given refractive indices. Recent advances in nanofabrication, characterization, and computational optics techniques have enabled the development of ultrathin metasurfaces,