Development of metalenses for the visible and near-infrared spectral ranges

Metalenses have emerged as a highly promising technology in the field of optics. They consist of minute structures organized on a substrate in two-dimensional arrays of subwavelength-spaced optical scatterers. Unlike the bulky nature of conventional lenses, metalenses feature a flat, lightweight design while delivering superior performance. By controlling light at the nanoscale, they enable extraordinary manipulation of light waves, offering benefits such as aberration correction, customized wavefront shaping, and improved focusing abilities. The DON team at the MPQ laboratory, where I completed my master’s internship, focuses on metalenses as one of their main research areas. The primary objective of my work was to fabricate metalenses using amorphous tita??nium dioxide (TiO2) for visible wavelengths and amorphous silicon (a-Si) for near-infrared (NIR) applications. This report outlines the critical steps in the fabrication process, highlighting essential technological techniques such as Atomic Layer Deposition (ALD) and Reactive Ion Etching (RIE). The aim is to provide a comprehensive examination of these processes and their roles in achieving the desired optical properties.