Monolithically integrated wide field-of-view metalens by angular dispersionless metasurface

Abstract

Meta-lenses, which are made by sub-wavelength metallic or dielectric elements, have attracted widespread attentions due to its unprecedented electromagnetic wave manipulation abilities and novel applications. Dissimilar to previous metalens doublet by all-dielectric metasurfaces in the optical band, an innovative and more robust approach by angular dispersionless meta-atom to directly eliminate aberrations in low spectrum is proposed. As a proof of concept, an elaborately selected singlet metallic resonator for simultaneously high transmission, full phase coverage and the ignored angular dispersion is presented in the microwave. The designed metalens with only one single phase gradient profile can focus wide field-of-view (FOV) incident waves of ± 40° with both a large numerical aperture of 0.56 (NA = 0.56) and high focusing efficiency of 53 % on average at microwave regime. The metalens is also fabricated by a single-step printed circuit board technique and the measured high-performance focusing are also achieved for the entire FOV. The presented on-chip and integrated wide FOV metalens provides a simple yet cost-effective method to develop wide-angle metalenses especially in low frequency band where plasmonic metasurfaces are commonly adopted. Besides, its excellent wide-angle focusing performances can satisfy diverse applications in modern radar engineering such as imaging, sensing, communications and detection, etc.