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Zhang Q, Liu D, Zhou S, Chen G, Su J, Sun L, Xiong Y, Li X. Quasi-Freeform Metasurfaces for Wide-Angle Beam Deflecting and Splitting. Nanomaterials (Basel) 2023; 13:1156. [PMID: 37049250 PMCID: PMC10097112 DOI: 10.3390/nano13071156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
Metasurfaces attracted extensive interests due to their outstanding ability to manipulate the wavefront at a subwavelength scale. In this study, we demonstrated quasi-freeform metasurfaces in which the radius, location, and height of the nanocylinder building blocks were set as optimized structure parameters, providing more degrees of freedom compared with traditional gradient metasurfaces. Given a desired wavefront shaping objective, these structure parameters can be collectively optimized utilizing a hybrid optimized algorithm. To demonstrate the versatility and feasibility of our method, we firstly proposed metasurfaces with deflecting efficiencies ranging from 86.2% to 94.8%, where the deflecting angles can vary in the range of 29°-75.6°. With further study, we applied our concept to realize a variety of high-efficiency, wide-angle, equal-power beam splitters. The total splitting efficiencies of all the proposed beam splitters exceeded 89.4%, where a highest efficiency of 97.6%, a maximum splitting angle of 75.6°, and a splitting uniformity of 0.33% were obtained. Considering that various deflecting angles, and various splitting channels with different splitting angles, can be realized by setting the optical response of metasurfaces as the optimization target, we believe that our method will provide an alternative approach for metasurfaces to realize desired wavefront shaping.
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Affiliation(s)
- Qiuyu Zhang
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China
- School of Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dingquan Liu
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China
- School of Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sheng Zhou
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
| | - Gang Chen
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
| | - Junli Su
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Leihao Sun
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Yunbo Xiong
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Xingyu Li
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China
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