Robust method of metrology for direct phase measurement for nano-antennas

Abstract

Optical metasurfaces allow the development of original and more and more complex optical functions. They are therefore facing a design and characterization problem. Indeed, they are more and more composed of complex patterns, with different types of antennas and non-periodic. This is why it is important to build libraries of nano-structures that can be used as building blocks to compose optical functions. Therefore, we propose a direct phase measurement metrology method for optical nanostructures. Using lateral shift interferometry, our technique allows to simultaneously characterize in amplitude and phase nano-antennas of all types, shapes and materials, and thus to experimentally establish a library of nano-antennas. Our method brings an additional tool in the design of nano-antennas, which completes the existing simulation tools, by allowing to test all types of nano-antennas.