Enhancement of nonlinear optic effect of the second harmonic generation in plasmonic waveguide using graphene and pyramid-shape gold nanoparticles

In this pioneering study, we introduce a sophisticated method to dramatically expand the Second Harmonic Generation (SHG) in plasmonic waveguides by ingeniously embedding pyramid-shaped gold nanoparticles inside a graphene matrix. Capitalizing on the exceptional electrical, thermal, and optical traits of graphene, our approach meticulously fine-tunes the nonlinear optical response, setting a new benchmark for SHG efficiency. Through an extensive exploration of the nanoparticle geometrical configuration, our findings underscore that the aspect ratio and specific spatial arrangement of gold nanoparticles are pivotal factors that considerably augment plasmonic light absorption, thereby elevating SHG performance. Notably, the incorporation of a gold-silver nanoparticle alloy into the matrix not only diversifies the material composition but also synergistically enhances the SHG output, surpassing traditional gold nanoparticle configurations by a significant margin. Our systematic optimization of nanoparticle attributes and the strategic interaction between graphene and metallic components reveal a novel pathway for engineering graphene-enhanced plasmonic devices. These devices are poised to revolutionize advanced optical applications, representing a significant leap forward in the realm of nonlinear photonics. This research delineates a transformative technique that could serve as the cornerstone for future innovations in the field.