Zeroth-order-free holographic reconstruction with a nanoimprinted nonlocal metasurface

Abstract

The undesired zeroth-order diffraction (ZOD) arising from imperfections in diffractive optical elements (DOEs) degrades the quality of target optical wavefronts. Herein, we propose a zeroth-order-free holographic reconstruction method using a nanoimprinted nonlocal metasurface. By judiciously designing the metasurface structure and its angular selectivity based on guided mode resonance, the ZOD can be suppressed without relying on a bulky, conventional 4f setup. We designed and fabricated a nanoimprinted nonlocal metasurface using a high-refractive-index TiO2-composite resin. Using the metasurface, we demonstrated ZOD suppression in a surface-relief DOE and a spatial light modulator. Furthermore, we prototyped a 20-mm-square metasurface and verified its effectiveness in suppressing the ZOD in 3D holographic projection.