MEMS Tunable Metalens Optics for MWIR Imaging

This effort aims to deliver a novel ultra-thin flat lens optics with a large aperture and active zoom capabilities that is based on metasurface metamaterial technology while being mindful of the size, weight, power, and cost. The proposed approach will achieve zoom through a tunable metalens system that operates using micro-electromechanical systems (MEMS) within a small and lightweight package for mid-wave infrared (MWIR) imaging. Unlike similar zoom metalenses that require large lateral displacement for zooming which are impractical for MEMS actuation, Phoebus’ approach uses vertical displacement of coupled layers which require displacements that are achievable by MEMS. Our developmental process consists of the metalens as simulated using a combination of rigorous coupled wave algorithm (RCWA) and a semi numerical beam propagation algorithm that is tuned for metalens simulations. The metalens system will be constructed from meta-atoms that house sub-wavelength geometries that sit on top of a transparent substrate. Each meta-atom design will be unique to a particular metalens, and they will be arranged to provide optimal transmission efficiency. To validate our approach, microfabrication will be used to fabricate a metalens test structure for optical characterization. The proposed design of the metalens system will use industry standard materials and fabrication processes that can be easily scaled up or down for manufacturing while being mindful of the cost.