Metasurfaces of gold (Au) nanoparticles on a SiO${}_2$-Si substrate were fabricated for the enhancement of second harmonic generation (SHG) using electron beam lithography and lift-off. Triangular Au nanoprisms which are non-centro-symmetric and support second-order nonlinearity were examined for SHG. The thickness of the SiO${}_2$ spacer is shown to be an effective parameter to tune for maximising SHG. Electrical field enhancement at the fundamental wavelength was shown to define the SHG intensity. Numerical modeling of light enhancement was verified by experimental measurements of SHG and reflectivity spectra at the normal incidence. At the plasmonic resonance, SHG is enhanced up to ∼3.5 × 10${}^3$ times for the optimised conditions.

中文翻译：

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从纳米棱镜的相工程后表面产生第二次谐波。

SiO上金（Au）纳米粒子的超表面${}_2$使用电子束光刻和剥离工艺制造了用于增强二次谐波（SHG）的-Si衬底。对于SHG，研究了非中心对称且支持二阶非线性的三角形Au纳米棱镜。SiO的厚度${}_2$隔离器被显示为调整以最大化SHG的有效参数。显示了在基本波长处的电场增强定义了SHG强度。通过对垂直入射的SHG和反射光谱进行实验测量，验证了光增强的数值模型。在等离子共振时，SHG增强至约3.5×10${}^3$ 优化条件的时间。