Reconfigurable Parfocal Zoom Metalens

摘要

Zoom lenses with variable focal lengths and magnification ratios are essentialfor many optical imaging applications. Conventional zoom lenses arecomposed of multiple refractive optics, and optical zoom is attained viatranslational motion of one or more lens elements, which adds to modulesize, complexity, and cost. In this paper, a zoom lens design based on multifunctionaloptical metasurfaces is presented, which achieves large step zoomratios, minimal distortion, and diffraction-limited optical quality withoutrequiring mechanical moving parts. Two embodiments of the concept areexperimentally demonstrated based on polarization-multiplexing in the visibleand phase change materials in the mid-infrared, both yielding 10× parfocalzoom in accordance with the design.