High-Efficiency, All-Dielectric Metasurfaces Down To The Deep Ultraviolet

In recent years, researchers have demonstrated various types of high-performance, all-dielectric metasurfaces operating in the infrared (IR) and visible regimes, paving the way towards high-efficiency, multi-functional and compact photonic systems. However, there has been a conspicuous lack of research on metasurfaces designed for operation in the ultraviolet (UV) region, which is the spectral region hosting various important applications such as photolithography, spectroscopy, astronomy, medical therapy, and high-resolution imaging. Unfortunately, direct scaling of the operation frequencies of metasurfaces based on the IR and visible designs down to the UV is challenging, due to the prohibitively high optical loss of typically employed constituent materials (e.g., Si, TiO ₂ , GaN).