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

TL;DR

This paper introduces dielectric metasurfaces capable of independently controlling both the amplitude and phase of light at one or two frequencies, enabling advanced holography with improved fidelity and new functionalities.

Contribution

It presents a simple, high-efficiency approach using meta-atoms with varying birefringence and rotation to achieve complete wavefront control, surpassing phase-only holography limitations.

Findings

Demonstrated holograms with independent amplitude and phase control at multiple frequencies.

Achieved artifact-free 2D holographic images and separate encoding of phase and amplitude.

Enabled control over surface textures of 3D holographic objects.

Abstract

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