Largest aperture metalens of high numerical aperture and polarization independence for long-wavelength infrared imaging

Abstract

Because of unique superiorities of planar optical devices based on metalens on manipulating amplitude, phase, polarization, wavelength of incident light, metalenses have great prospects to replace traditional catadioptric optical components, especially in imaging and optoelectronic integration. However, the research of metalens has focused on visible or near-infrared wavelength in the past few years and little attention was paid to the long-wavelength infrared metalens. Here, we demonstrate the largest aperture, high numerical aperture, and polarization-independent metalens operating at long-wavelength infrared. The metalens has a numerical aperture of 0.45 at the center wavelength of10 µm. The aperture of the metalens is 80 mmwhich is much larger than the existing level we know. It has high-resolution imaging ability with focusing incident light down to a spot as small as ∼1.04λ. Ambient light imaging experiments are carried out to show the performance of the metalens. In addition, metalens is flimsy, large-scale and low-cost, which provides an effective solution for the development of ultra-lightweight and compact optical devices for LWIR technology.