Diffractive VO2 metagrating for strong multi-objective amplitude modulation of optical reflection

摘要

Ultracompact dynamic modulation of light waves in free space has been one of the most desired goals in the field of optics and photonics. Recently, various strategies of combining optical metasurfaces and phase-change materials with largely reconfigurable optical properties have been in the spotlight for this challenging goal. However, intuitive, step-by-step design rules of a dynamic metasurface to meet multi-objective, high-performance modulation of optical beams have not been reported. I propose a theoretical and numerical study on the vanadium dioxide based diffractive metagrating exhibiting strong modulation of reflectance meeting multiple on-demand performance objectives, simultaneously. Leveraging the large dielectric-to-metal phase-change of vanadium dioxide and a non-resonant diffractive metagrating, multi-objective modulation of reflection intensity is achieved with large on-state reflectance, near-unity modulation depth, broad bandwidth, amplitude-only modulation, and further elimination of higher order diffractions. (C) 2021 Optical Society of America