瑞利判据启发的可见光波段宽带消色差偏振不敏感超构透镜的设计  

Broadband achromatic and polarization-insensitive metalenses in the visible inspired by Rayleigh criterion

作　　者：姚克敏 许军伟 田喜敏 许坤[1] 付林杰 潘靓 冀宇航 潘晓宇 YAO Kemin;XU Junwei;TIAN Ximin;XU Kun;FU Linjie;PAN Liang;JI Yuhang;PAN Xiaoyu(School of Materials Science and Engineering,Zhengzhou University of Aeronautics,Zhengzhou 450046,China)

机构地区：[1]郑州航空工业管理学院材料学院,河南郑州450046

出　　处：《红外与激光工程》2024年第10期216-226,共11页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(12004347);河南省重点研发与推广专项(科技攻关)(242102211081,232102320057);河南省高校重点科研项目(24A140025);河南省青年骨干教师项目(2023GGJS113);航空科学基金项目(2020Z073055002);河南高校重点科研项目基础研究专项计划项目(22ZX012);郑州航空工业管理学院大学生创新创业训练计划项目(202410485031);郑州航空工业管理学院实验室开放项目(ZHSK24-37)。

摘　　要：超构表面作为亚波长结构单元排布而成的新型平面光学元件,可对光场相位、振幅、偏振及频率进行灵活剪裁,为光学元件集成化和小型化提供了强大的支撑平台。超构透镜是超构表面最重要的应用之一,消色差对于超构透镜的成像质量至关重要。然而,受限于超构元胞共振色散及有限共振带宽,超构透镜在偏离设计波段会遭受较大的色差,从而限制了其在多波长或连续宽带器件中的应用。为此,文中基于焦斑分辨瑞利判据(Rayleigh criterion)原理,提出了一种面向可见光波段宽带消色差偏振不敏感超构透镜的新型设计策略。通过采用共轭相位自旋复用设计理论,将面向两边缘波长、高效工作、两尺寸不同、各向异性的TiO_(2)纳米柱(均具备半波片功能)的旋转角度限制在0°或90°,作为一复合超构胞元构建超构透镜。通过两纳米柱之间的色散互补效应,实现了在可见光波段(λ=470~650 nm)宽带消色差偏振不敏感聚焦性能,同时保持了较高聚焦效率。这一工作为宽带消色差超构透镜的设计领域带来了重大进步,并有望在超紧凑芯片级设备中实现潜在应用。Objective Metasurfaces,a planar optical element composed of subwavelength structural units,can flexibly tailor the phase,amplitude,polarization,and frequency of the optical field,providing a robust platform for the integration and miniaturization of optical components.Metalenses stand out as a crucial application of metasurfaces,with achromatism playing a key role in ensuring high imaging quality.Nonetheless,the existence of metacell resonances with varying dispersions and restricted resonance bandwidths causes metalenses to display considerable chromatic aberrations when functioning beyond the specified wavelength range,thereby hampering their utility in multi-wavelength or broadband applications.To tackle this challenge,this paper proposes a novel design strategy for visible broadband achromatic and polarization-insensitive metalenses,guided by the Rayleigh criterion principle for resolving the focal spot.By leveraging the theory of conjugate phase spin multiplexing design,a composite metacell element of metalenses is constructed using two differently-sized anisotropic TiO_(2) nanofins that operate efficiently at two distinct edge wavelengths,with their rotation angles limited to 0°or 90°.Through the complementary dispersion effects between the two nanofins,this design achieves wideband achromatism and polarization-insensitive focusing performance in the visible light spectrum(λ=470-650 nm),while maintaining high focusing efficiency.This advancement marks a significant step forward in the realm of broadband achromatic metalenses and paves the way for potential applications in compact,chip-level devices.Methods Inspired by the Rayleigh criterion for spot resolution,this work presents a novel design strategy for visible broadband achromatic and polarization-insensitive metalenses.By utilizing the Pancharatnam-Berry(PB)phase and leveraging the theory of conjugate phase spin multiplexing,we construct metalenses using two sets of anisotropic TiO_(2) nanofins that operate efficiently at two distinct edge wavelengt

关 键 词：超构透镜 宽带消色差 偏振不敏感聚焦 色散互补效应 

分 类 号：O438[机械工程—光学工程]