Transmission Gratings relying on Huygens Metasurfaces for short-wave to long-wave infrared applications

Abstract

In many spectroscopic applications, diffraction gratings are the pivotal optical component which is used to decompose white light into its spectrum. However, design and manufacturing of diffraction gratings for the infrared spectral domain operating in transmission bares its own challenges, i.e. a very limited choice of transparent materials. Here we present our effort on exploiting Huygens-metasurface structures for design and manufacturing of diffraction gratings intended for operation in the short-wave (around 2µm) up to the long-wave infrared region (>10µm). Silicon nano-pillars are the material system of choice since they exhibit the best compromise between optical performance and manufacturing feasibility. We present specific designs as well as measurement results of a demonstrator sample.