Large-aperture imaging system based on 100 mm all-Si metalens in long-wave infrared

Abstract Metalens, which composed of micro-nano structures at sub-wavelength scale, possessing the ability to achieve the functions of traditional lens elements, paving the way for the development of lightweight and integrated imaging systems. Nowadays, the majority of research efforts in the field of metalens have been concentrated on the exploitation of short optical wavelength band with tiny apertures. Here, we have directed our focus towards the long-wave infrared (LWIR) band, which holds significant importance for crucial applications like infrared imaging and detection. We have prepared a metalens with a remarkable aperture of 100 mm and a high numerical aperture of 0.89 at an operating wavelength of 9.35 μ m, which is currently the largest reported aperture in LWIR with high light harvesting capability. And the imaging performance was verified by demonstrating the imaging results of the metalens on targets with different temperatures through thermal imaging tests.