Non-mechanical reconfigurable zoom metalenses

Zoom lenses with adjustable focal lengths and magnification ratios are an crucial part for many optical imaging systems. Conventional zoom lenses comprise multiple refractive optics. Optical zoom is achieved with translational motion of multiple lens elements, which inevitably increases module size, cost, and complexity. Here, we present a zoom lens design based on multi-functional optical metasurfaces. It achieves large zoom ratios with diffraction-limited quality and minimal distortion. Also, it requires no mechanical moving parts. We demonstrate the concept with two embodiments, one in the visible with polarization-multiplexing, and the other in the mid-infrared with phase change materials. Both of them achieve 10x parfocal zoom consistent with the design.