Investigation of Material Properties for Use in UV Metasurfaces

The conventional use of UV light -between the wavelengths 200 and 400nm - is limited due to difficulties in controlling its properties. Still, it has huge potential for applications, particularly in medicine (pharmacology, phototherapy, ophthalmology, dermatology and sanitation) and nanotechnology (high-resolution lithography).Metasurfaces are structured surfaces with a wide range of specific functionalities, from standard ones like lenses and polarisers to more complex ones, including beam shaping, beam splitting and light modulation. They are used in different wavelength ranges, starting from visible and ending in the radio range, where they are generally known as frequency-selective surfaces. The main bottleneck in developing dielectric metasurfaces for UV light is that there are limited materials available. The situation is similar to the one in plasmonic research several years ago when a massive effort was aimed at finding alternative plasmonic materials. Most conventional dielectrics for visible and near-infrared optics are extremely lossy in the UV range, making them unsuitable for optical purposes. In this paper, we will present an initial investigation of the properties of several materials we have identified that have the potential to be used in fabricating UV MSs. We will discuss the various optical properties but also asses their feasibility from a nanofabrication point of view.