High-performance meta-devices based on multilayer meta-atoms:interplay between the number of layers and phase coverage

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2019,（12）
• 页码范围: 823-835
• 页数: 13页
• 语种: 英文

摘要

Transmissive metasurfaces have provided an efficient platform to manipulate electromagnetic (EM)waves,but previously adopted multilayer meta-atoms are too thick and/or the design approach fully relies on brute-force simulations without physical understandings.Here,based on coupled-mode theory (CMT) analyses on multilayer meta-atoms of distinct types,it is found that meta-atoms of a specific type only allows the phase coverage over a particular range,thus suitable for polarization-control applications.However,combinations of meta-atoms with distinct types are necessary for building ultra-thin wavefront-control meta-devices requiring 360° phase coverage.Based on these physical understandings,high-efficiency meta-atoms are designed/fabricated,and used to construct three typical meta-devices,including quarter-and half-wave plates and a beam deflector.Our results elucidate the physics underlying the interplay between thicknesses and performances of transmissive metasurfaces,which can guide the realizations of miniaturized transmissive meta-devices in different frequency domains.