Continuous zoom metalens based on the polarization state of light source in the ultraviolet band

Abstract

Zoom metalenses operating in the ultraviolet band have high resolution and flexibility, which can achieve accurate imaging and detection of tiny objects. It is useful for applications requiring high-intensity ultraviolet light, such as photolithography in semiconductor manufacturing, cell imaging in biomedical field, ultraviolet imaging and detection, ultraviolet catalysis, etc. However, most zoom systems need double-layer structure or complex mechanical tuning mode, which makes it difficult to achieve miniaturization due to its large volume. Here, an all-dielectric single-layer zoom metalens in the ultraviolet band is designed by changing the polarization state of the incident light. The focal length, focal depth, and focusing efficiency of the metalens are discussed when different polarized light sources are incident. The metalens uses (AlxGa1−x)2O3 material to achieve continuous focal length control at the wavelength of 365 nm, and the focusing efficiency is maintained at about 80%. The zoom metalens has the advantages of small volume, compact surface, flexible control, and fine adjustment. It is widely used in small mobile devices, precision medical systems, advanced optical components, etc.