High‐Performance Broadband Circularly Polarized Beam Deflector by Mirror Effect of Multinanorod Metasurfaces

Abstract

wileyonlinelibrary.comantennas and metallic patches were also proved to be able to manipulate wavefront of scattered waves for refracted or refl ected light. [4][5][6][7][8][9][10][11][12] Among these new-type anomalous-scattering devices, the control of circularly polarized (CP) light is testifi ed feasible in both theory and experiment-with spatially various antennas arranged properly. The phase of CP light is modulated without paying attention on scattered intensity generated by each antenna. [13][14][15][16][17] Harnessing light for modern photonic applications often involves the control and manipulation of light intensity or effi ciency. The most important issue for generating anomalous scattered lights is also the effi ciency by reasonable arrangement of the various shaped or layered plasmonic metasurfaces. Compared with normal light conforming to ordinary Snell's law, the effi ciency of the anomalous scattered lights is far too low in the previous works. Some methods have been proposed to improve the intensity of abnormal light but at the same time suppress that of normal one. For example, plasmonic metasurface can be sandwiched by gratings to increase the effi ciency of cross-polarized light with the help of Fabry-Pérot effect; [ 18,19 ] or few-layer composite metascreen made of dielectric and metal is used to enhance the performance of control. [ 20,21 ] These approaches dramatically enhance the effi ciency of anomalous light, but at the same time increase the processes and diffi culty in fabrication because of their extra structures (gratings or board) and precise distance between antennas and gratings. However, so far it is still challenging to further improve the effi ciency of anomalous light with circular polarization by a single-layer plasmonic metasurface.Here, we introduce a new approach to describe the function of a polarizer and show an intuitive method to describe the extra phase of CP light due to its orientation. We present the design, fabrication, and characteristics of the multinanorod plasmonic metasurfaces, in which each unit can be regarded as an imperfect polarizer with extraordinary broadband. The high effi ciency and broadband effects are theoretically and experimentally demonstrated. The correctness of GSL is also demonstrated by experimental results. At last, arbitrary polarized incidence is considered, and an easy way to determine the polarization degree of the incident light based on Poincaré sphere is feasibly proved by the proposed plamonic metasurfaces. High-Performance Broadband Circularly Polarized Beam Defl ector by Mirror Effect of Multinanorod MetasurfacesZhaocheng Liu , Zhancheng Li , Zhe Liu , Jianxiong Li , Hua Cheng , Ping Yu , Wenwei Liu , Chengchun Tang , Changzhi Gu , Junjie Li , * Shuqi Chen , * and Jianguo Tian * Manipulation of light phase and amplitude by plasmonic metasurfaces has immensely promising applications in optical imaging, information processing, communications, and quantum optics. However, the controllability of effi ciency and bandwidth is relati...

Vertically‐Stacked Discrete Plasmonic Meta‐Gratings for Broadband Space‐Variant Metasurfaces

“…The region where the polarization conversion efficiency is greater than 40% is highlighted by the shaded gray area. Comparing with previous works, [ 16,39–42 ] the working bandwidth is improved without sacrificing the transmission efficiency. In the bottom panel of Figure 2c, there are two peaks for the cross‐polarized transmission: one at 680 nm and another at 1254 nm with efficiency of 32.2% and 50.2%, respectively.…”

“…We found that the polarization conversion performance of SR-based VSPMG is nearly identical with TR-based meta-grating when both of them are particularly optimized to work at the same central wavelength. We emphasize that the proposed VSPMG outperforms previous plasmonic metasurface works [16,17,39,40] in terms of the peak efficiency and working bandwidth. The quantitative comparison of this work with the prior art is given in Table S1 (Supporting Information).…”

Simultaneous generation of high-efficiency broadband asymmetric anomalous refraction and reflection waves with few-layer anisotropic metasurface

“…The efficiency of our proposed metasurface is higher than 45% in a 150 nm bandwidth and the intensity of normal waves are no more than 20%. With this criterion, the bandwidths of typical single-layer metasurface are equal to zero 5 6 7 8 , thereby the proposed few-layer design overcomes the limited bandwidth and low efficiency of previous single-layer devices and is proved to be quite beneficial for practical applications.…”

Completely Spin-Decoupled Dual-Phase Hybrid Metasurfaces for Arbitrary Wavefront Control

“…Both metadevices are designed to operate at f 0 = 10.5 GHz, and each consists of 27 × 27 anisotropic subwavelength meta-atoms, occupying a total size of D × D = 256.5 × 256.5 mm 2 . The first metasurface (metadevice I) is designed to exhibit two functionalities: a linear phase profile for an oblique planar wavefront (anomalous reflection − ) at the LCP state φ 1 ( x , y ) = ξ y , with ξ = 2π/ L = 0.5 k 0 ( L = 57 mm being the super periodicity), and a spherical phase profile for focusing at the RCP state, with (with F = 153.9 mm being the focal length and λ the working wavelength). The second metasurface (metadevice II) generates a diffraction-free Bessel beam − for an incident LCP wave, with ( F = 153.9 mm being the long depth of focus and R half of the axicon aperture), a highly directive quad pencil beam at (φ = 0°, 90°, 180°, 270°; θ = 45°) for an incident RCP wave with φ 2 ( x , y ) = φ Quad‑beam synthesized based on an alternating projection method (APM); see Figure S4a in the Supporting Information for the phase and APM details.…”