Infrared Upconversion Imaging Based on Membrane Silicon Metasurface

Nonlinear nanophotonics has been attracting tremendous attention due to its vast applications in sensing, optical microscopy, and quantum photon source generation. Nonlinear metesurfaces have been recognised as a potential substitute for commercial IR imaging and spectroscopy detectors because of their superiority of being ultra-compact, and containing fewer components for signal conversion [1]. Here, we propose silicon membrane metasurfaces with smaller unit-cell sizes (Fig. 1a) to enhance local light confinement and to increase the conversion efficiency and spatial resolution of the third-harmonic generation (THG) in IR imaging applications [2].