title: Plasmon-enhanced second-harmonic generation from hybrid ZnO-covered silver-bowl array.
abstract: High-efficient, plasmon-enhanced nonlinear phenomena based on hybrid nanostructures, which combine nonlinear dielectrics with plasmonic metals, are of fundamental importance for various applications ranging from all-optical switching to imaging or bio-sensing. However, the high loss of the excitation energy in nanostructures and the poor spatial overlap between the plasmon enhancement and the bulk of nonlinear materials largely limit the operation of plasmon-enhanced nonlinear effects, resulting in low nonlinear conversion efficiency. Here, we design and fabricate a ZnO-covered, 2D silver-bowl array, which can serve as an efficient platform for plasmon-enhanced second-harmonic generation (PESHG). Validated by experiments and simulations, we demonstrate that the high spatial overlap between the near-field enhancement and the ZnO film plays the key role for this nanostructure-based PESHG process. The enhancement mainly originates from the fundamental wavelength-derived plasmon resonance, providing an enhancement factor of approximately 33 times. These results achieved pave the way for future applications, which require localized light sources at nanoscale.
authors.affiliation: Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Yang
authors.forename: Shaoxin
authors.initials: S
authors.lastname: Shen
authors.forename: Xiangjie
authors.initials: X
authors.lastname: Wang
authors.forename: Binbin
authors.initials: B
authors.lastname: Yu
authors.forename: Shengli
authors.initials: S
authors.lastname: Huang
authors.forename: Die
authors.initials: D
authors.lastname: Xu
authors.forename: Jiawen
authors.initials: J
authors.lastname: Hu
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Yang