Dielectric Metasurfaces for Complete and Independent Control of Optical\n Amplitude and Phase

Abstract

Metasurfaces are optically thin metamaterials that promise complete control\nof the wavefront of light but are primarily used to control only the phase of\nlight. Here, we present an approach, simple in concept and in practice, that\nuses meta-atoms with a varying degree of form birefringence and rotation angles\nto create high-efficiency dielectric metasurfaces that control both the optical\namplitude and phase at one or two frequencies. This opens up applications in\ncomputer-generated holography, allowing faithful reproduction of both the phase\nand amplitude of a target holographic scene without the iterative algorithms\nrequired in phase-only holography. We demonstrate all-dielectric metasurface\nholograms with independent and complete control of the amplitude and phase at\nup to two optical frequencies simultaneously to generate two- and\nthree-dimensional holographic objects. We show that phase-amplitude\nmetasurfaces enable a few features not attainable in phase-only holography;\nthese include creating artifact-free two-dimensional holographic images,\nencoding phase and amplitude profiles separately at the object plane, encoding\nintensity profiles at the metasurface and object planes separately, and\ncontrolling the surface textures of three-dimensional holographic objects.\n