Spin-encoded multifunctional meta-holographic display

Abstract

Multi-operational metasurfaces have received a lot of interest because of their significant design improvements for ultra-compact and highly integrated meta-optics. The emergence of near and far-field holography offers an effective solution to enhance the capacity of information encoding in a single metasurface. However, the existing strategies of layer stacking and interleaving, where distinct functionalities are embedded with the help of the combination of multiple meta-atoms, have challenges in terms of design complexity and efficiency. This manuscript proposes a new simplest approach for a tri-channel highly efficient meta-holography based on the photonics spin Hall Effect (PSHE) and Mauls’ Principle of amplitude manipulation. A multi-functional metasurface constituent of a single nano-rectangular pillar over a glass substrate is designed as evidence of conception to highlight the feasibility of parallel manipulation upon near and far-field activities. To achieve control over the entire phase range (0-2π), geometric phase modulation is utilized. Zinc sulphide (ZnS) is used as a constituent material for highly efficient broadband response over the whole visible spectrum due to its characteristics of an extraordinary refractive index and low absorption coefficient. For authentication of the proposed methodology, the designed metasurface is simulated in FDTD, effectively validating the execution of a multi-functional design scheme. For the proof of the broadband operation, optical response over three visible wavelengths (i.e., blue, green, and red) is measured, and it reconstructs all three holograms with high efficiency. Thus, the proposed optical response multiplication approach is a viable contender for various high-end applications in photonics, data storage, and communication.