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• Chinese Optics Letters
• Vol. 20, Issue 5, 053602 (2022)
Samia Osman Hamid Mohammed1, Dong Zhao1, Syed Yasir Azeem1, Xiaoming Goh2, Shawn J. Tan2, Jinghua Teng2、**, and Kun Huang1、*
Author Affiliations
• 1Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei 230026, China
• 2Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore
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Samia Osman Hamid Mohammed, Dong Zhao, Syed Yasir Azeem, Xiaoming Goh, Shawn J. Tan, Jinghua Teng, Kun Huang. Efficiency-enhanced reflective nanosieve holograms[J]. Chinese Optics Letters, 2022, 20(5): 053602 Copy Citation Text show less

Abstract

Photon nanosieves, as amplitude-type metasurfaces, have been demonstrated usually in a transmission mode for optical super-focusing, display, and holography, but the sieves with subwavelength size constrain optical transmission, thus leading to low efficiency. Here, we report reflective photon nanosieves that consist of metallic meta-mirrors sitting on a transparent quartz substrate. Upon illumination, these meta-mirrors offer the reflectance of $∼50%$, which is higher than the transmission of visible light through diameter-identical nanoholes. Benefiting from this configuration, a meta-mirror-based reflective hologram has been demonstrated with good consistence between theoretical and experimental results over the broadband spectrum from 500 nm to 650 nm, meanwhile exhibiting total efficiency of $∼7%$. Additionally, if an additional high-reflectance layer is employed below these meta-mirrors, the efficiency can be enhanced further for optical anti-counterfeiting.

1. Introduction

Photon sieves composed of etched holes on an opaque film have been proposed firstly, to the best of our knowledge, to reduce the focal spot size and alleviate high diffraction orders in soft X-ray and the optical spectrum[1]. With the rapid development of nano-fabrication technology, photon sieves have been demonstrated at nanoscale and worked as binary-amplitude metasurfaces for optical focusing[2,3]. The photon nanosieves have the advantages of polarization independence and more degrees of freedom in design than the concentric rings in zone plates[4], which therefore enable more complex manipulation of light, such as hologram[2,5], by arranging the locations of holes in a customized way. Due to the subwavelength feature of nanosieves, their related holograms usually support broadband operation[6]. In addition, the non-resonating mechanism of amplitude modulation makes the nanosieve hologram have a wider spectrum than other metasurface devices with resonating nano-structures[7]. The nanosieve hologram also enables a large field of view for holographic display when combined with tunable phase realized by a spatial light modulator[8]. Beyond the circular shape, rectangle nanosieves have also been proposed to control the geometric phase of a circularly polarized light by rotating the orientations of the rectangular nanosieves[9,10], thus enabling full-color holography[11] and the generation of optical vortices[10,1214] in various electromagnetic spectra such as X-ray and vacuum ultraviolet wavelengths[7,15,16].

Copy Citation Text
Samia Osman Hamid Mohammed, Dong Zhao, Syed Yasir Azeem, Xiaoming Goh, Shawn J. Tan, Jinghua Teng, Kun Huang. Efficiency-enhanced reflective nanosieve holograms[J]. Chinese Optics Letters, 2022, 20(5): 053602