Augmentation of surface plasmon-enhanced second harmonic generation from Au nanoprisms on SiO2/Si: interference contribution

We present an augmentation of Surface Plasmon (SP)-enhanced second harmonic generation (SHG) due to interference field enhancement in Au nanoprisms (AuNPs) on SiO2-coated Si substrates. The SiO2 spacer contributed for the optical interference and increased the coupling efficiency of the pump light with the SP polarization as well as a decoupling efficiency of the SHG waves from nonlinear polarization. The intensity of the SP-enhanced SHG signals increased 4.5-fold with respect to the AuNPs on the bare SiO2 substrate by setting the SiO2 spacer layer to the appropriate thickness. The numerical analysis revealed that the optimal SHG conversion was determined by the balance between the degree of the optical interference at the fundamental and SHG wavelengths. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this study, an augmentation of Surface Plasmon (SP)-enhanced second harmonic generation (SHG) was presented using Au nanoprisms (AuNPs) with interference field enhancement. The SiO2 spacer layer contributed to optical interference and increased the coupling efficiency of pump light with SP polarization, as well as improved the decoupling efficiency of SHG waves from nonlinear polarization. By adjusting the thickness of the SiO2 spacer layer, the intensity of SP-enhanced SHG signals was significantly increased.