Hähnel David, Golla Christian, Albert Maximilian, Zentgraf Thomas, Myroshnychenko Viktor, Förstner Jens, Meier Cedrik
Theoretical Electrical Engineering & CeOPP, Paderborn University, 33098, Paderborn, Germany.
Physics Department & CeOPP, Paderborn University, 33098, Paderborn, Germany.
Light Sci Appl. 2023 Apr 21;12(1):97. doi: 10.1038/s41377-023-01134-1.
We present strong enhancement of third harmonic generation in an amorphous silicon metasurface consisting of elliptical nano resonators. We show that this enhancement originates from a new type of multi-mode Fano mechanism. These 'Super-Fano' resonances are investigated numerically in great detail using full-wave simulations. The theoretically predicted behavior of the metasurface is experimentally verified by linear and nonlinear transmission spectroscopy. Moreover, quantitative nonlinear measurements are performed, in which an absolute conversion efficiency as high as η ≈ 2.8 × 10 a peak power intensity of 1.2 GW cm is found. Compared to an unpatterned silicon film of the same thickness amplification factors of up to ~900 are demonstrated. Our results pave the way to exploiting a strong Fano-type multi-mode coupling in metasurfaces for high THG in potential applications.
我们展示了由椭圆形纳米谐振器组成的非晶硅超表面中三次谐波产生的强烈增强。我们表明，这种增强源于一种新型的多模法诺机制。使用全波模拟对这些“超法诺”共振进行了非常详细的数值研究。通过线性和非线性透射光谱对超表面的理论预测行为进行了实验验证。此外，还进行了定量非线性测量，其中发现绝对转换效率高达η≈2.8×10，峰值功率强度为1.2GW/cm。与相同厚度的无图案硅膜相比，放大倍数高达约900。我们的结果为在潜在应用中利用超表面中强烈的法诺型多模耦合实现高三次谐波产生铺平了道路。
