Resonant Anti-Reflection Metasurface for Infrared Transmission Optics

Abstract: A fundamental capability for any transmissive optical component is anti-reflection, yet this capability is challenging to achieve in a cost-efficient manner over longer infrared wavelengths. We demonstrate that Mie resonant nanophotonic structures enhance transmission in Silicon, allowing it to function as an effective optical material over long-wave infrared wavelengths. This approach enables a window optic with up to 40\% greater transmission than equal thickness unpatterned Si. Imaging comparisons with unpatterned silicon and off-the-shelf Germanium optics are shown, as well as basic broadband slant edge MTF measurements. Overall, we demonstrate how Mie-resonant structures can be used to improve optical transmission through window optics of arbitrary lithographically patternable optical media, and highlight their possible use in imaging applications.