The second harmonic generation (SHG) of vertical and planar split‐ring resonators (SRRs) that are broken centro‐symmetry configurations at the interface of metal surface and air is investigated. Strong interactions, better electromagnetic field confinements, and less leakage into the substrate for vertical SRRs are found. Experimental results show a 2.6‐fold enhancement of SHG nonlinearity, which is in good agreement with simulations and calculations. Demonstrations of 3D metastructures and vertical SRRs with strong SHG nonlinearity majorly result from magnetic dipole and electric quadrupole clearly provides potential applications for photonics and sensing.

中文翻译：

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垂直开环谐振器的二次谐波光处理

研究了垂直和平面开口环谐振器（SRR）的二次谐波产生（SHG），这些谐振器在金属表面和空气的界面处的中心对称配置被破坏。对于垂直SRR，发现了强大的相互作用，更好的电磁场限制以及更少的泄漏到基板中。实验结果表明，SHG非线性增强了2.6倍，与仿真和计算非常吻合。具有强SHG非线性的3D元结构和垂直SRR的演示主要是由磁偶极子和电四极子产生的，显然为光子学和传感提供了潜在的应用。