Focus control of wide-angle metalens based on digitally encoded metasurface
基于数字编码元曲面的广角金属透镜聚焦控制
デジタルエンコード元曲面に基づく広角金属レンズフォーカス制御
디지털 코딩 메타서피스 기반 광각 금속 렌즈 초점 제어
Control de enfoque de lentes metálicas de gran ángulo basado en la superficie del elemento de codificación digital
Contrôle de mise au point de lentille métallique grand angle basé sur une méta - surface codée numériquement
управление фокусировкой широкоугольной металлической линзы на кривой цифрового кодирующего элемента
Yi Chen 陈义 ¹, Simeng Zhang 章思梦 ¹ ², Ying Tian 田颖 ¹, Chenxia Li 李晨霞 ¹, Wenlong Huang 黄文龙 ¹, Yixin Liu 刘熠昕 ¹ ², Yongxing Jin 金永兴 ¹, Bo Fang 方波 ³, Zhi Hong 洪治 ² ⁴, Xufeng Jing 井绪峰 ² ⁴
¹ Institute of Optoelectronic Technology, China Jiliang University, Hangzhou 310018, China
中国 杭州 中国计量大学 光电材料与器件研究院
² Centre for THz Research, China Jiliang University, Hangzhou 310018, China
中国 杭州 中国计量大学 太赫兹技术与应用研究所
³ College of Metrology & Measurement Engineering, China Jiliang University, Hangzhou 310018, China
中国 杭州 中国计量大学 计量测试与仪器学院
⁴ College of Information Engineering, China Jiliang University, Hangzhou 310018, China
中国 杭州 中国计量大学信息工程学院
Based on the principle of super-symmetric lens with quadratic phase gradient transformation, combined with the principle of digital coding of metasurface, we propose a wide-angle coded metalens for focusing control in two-dimensional space. This metalens achieves focus shift in the x-direction by changing the oblique incidence angle of the incident wave, and focus control in the y-direction by combining with the convolution principle of the digitally coded metasurface to achieve flexible control of light focusing in the two-dimensional plane.
The metasurface unit is mainly composed of three-layer of metal structure and two layers of medium, and the transmission phase is obtained by changing the middle layer of metal structure, which in turn obtains the required phase distribution of the metalens. The design of the metalens realizes the function of the lens with a large viewing angle at the x-polarized incidence, and realizes two-dimensional focus control.
Experimentally, we prepared the designed coding metalens and tested the focus control function of the wide-angle coding metalens. The experimental results are in good agreement with the design results.
