Chen Huan, Chen Xin, Zhao Xiaopeng, Wang Junli
School of Physics, Xidian University, Xi'an, 710071, People's Republic of China.
Guangzhou Institute of Technology, Xidian University, Guangzhou, 510555, People's Republic of China.
Nanotechnology. 2023 Nov 3;35(3). doi: 10.1088/1361-6528/ad0484.
The preparation of the vast majority of nonlinear optical metal metasurfaces currently relies on complex top-down methods such as electron beam or ion beam etching, which are expensive and difficult to meet the requirement of large area preparation. In this paper, an easily prepared quasi-periodic silver dendritic metasurface model with highfactor is established in the near-infrared band based on a simple and easy-to-operate electrochemical deposition method. The simulations prove that the silver dendritic metasurface has a highfactor (exceeds 10) because of its strong electric field localization ability, which is analogous to the superposition of multiple split-ring resonators. It is demonstrated that the second harmonic generation (SHG) intensity of the dendritic metasurface at a large incident angle (such as 85°) is about 30 times that of the metasurface at a small incident angle when the-polarized pump light is incident obliquely to break the centrosymmetry of the metasurface. The influences of the incident angle or dendritic structure's dimensions on thefactor and SHG efficiency have also been researched through a lot of simulation. This easily prepared quasi-periodic silver dendritic metasurface SHG device may provide a new avenue for the development and application of miniature, integratable nonlinear optical devices.
目前，绝大多数非线性光学金属超表面的制备依赖于电子束或离子束蚀刻等复杂的自上而下方法，这些方法成本高昂，且难以满足大面积制备的需求。本文基于一种简单易操作的电化学沉积方法，在近红外波段建立了一种易于制备的高因子准周期银树枝状超表面模型。模拟结果表明，银树枝状超表面由于其强电场局域化能力而具有高因子（超过10），这类似于多个裂环谐振器的叠加。结果表明，当偏振泵浦光斜入射以打破超表面的中心对称性时，树枝状超表面在大入射角（如85°）下的二次谐波产生（SHG）强度约为小入射角下超表面的30倍。通过大量模拟研究了入射角或树枝状结构尺寸对因子和SHG效率的影响。这种易于制备的准周期银树枝状超表面SHG器件可能为微型、可集成非线性光学器件的开发和应用提供一条新途径。
