Fabrication and validation of meta-optics for infrared imaging applications

Infrared meta-optics are a promising technology for infrared imaging applications: they are compact, lightweight and can have dramatically lower manufacturing costs than traditional optics. However, the adoption of meta-optics for defense applications requires rigorous validation of their optical performance, stray light characteristics, and manufacturability. In this work, we report on Leidos’ meta-optics modeling, nanofabrication and characterization capabilities, showing that simulated and experimentally obtained diffraction efficiencies of meta-optics manufactured using scalable fabrication agree over a wide spectral band in the mid-wave infrared. The meta-optics are 3-inch diameter lenses fabricated on 100 mm silicon wafers using photolithography and reactive ion etching. Scanning electron micrographs inform the meta-atom geometry in our electromagnetics models. We compare samples etched by an external vendor to those etched at Leidos, and show that geometric perturbations, specifically shape distortions and sidewall angle, can be accounted for in our simulations. This work demonstrates that deviations from as-designed performance and biases in the manufacturing pipeline can be identified, enabling correction through modifications to meta-lens design, fabrication, or both. Our self-consistent model can be integrated into commercial optical design software to enable meta-optic/refractive co-design and to predict system-level stray light behavior.