Mid-infrared large-aperture metalens design verification and double-layer micro-optical system optimization

In this article, we explored the design and simulation techniques of large-aperture metalenses, and the optimization design methods of metalenses. For verification and experimental demonstration, a centimeter-scale aperture single-layer metalens and a field of view optimized metalens doublet,composed of subwavelength-spaced Si nanopillars with an operating wavelength of 3.77 µm were designed and manufactured. Finally, the focusing performance of the two under narrow-band laser irradiation was characterized, and an imaging demonstration of the metalens doublet was performed under an optical bandwidth of 250 nm (3500-3750 nm). We envision that the calculation, design, sample manufacturing and demonstration research on large-aperture metalens presented here will provide an important reference for the design and verification of large-aperture metasurface lenses or special metasurface devices in the future, such as large-aperture compact multifunctional metalens optical equipment for low-load special application systems like airborne, spaceborne, missile, satellite and deep sea.