Competitive Effects of Surface Plasmon Resonances and Interband Transitions on Plasmon-Enhanced Second-Harmonic Generation at Near-Ultraviolet Frequencies

• DOI: 10.1103/physrevapplied.13.024045
• Publication Date: 2020-02-21T16:07:31Z
• Authors: Shaoxin Shen; Jiejie Shan; Tien-Mo Shih; Junbo Han; Zongwei Ma; Feng Zhao; Fangzu Yang; Yongliang Zhou; Zhilin Yang
• Keywords: Ultraviolet; Localized surface plasmon

The competition between plasmonic resonances and noble-metal interband transitions at near-ultraviolet (NUV) frequencies complicates nonlinear conversion processes nanoscales. Here, we experimentally design a highly enhanced reproducible plasmon-enhanced second-harmonic generation (PESHG) platform suitable for NUV by constructing three-dimensional silver mushroom arrays. SHG emission from proposed platforms involved in geometrical asymmetry greatly outperforms that unpatterned metallic films. Studies among arrays with various geometric parameters weight ratios of component materials enable us to distinguish characteristics exhibited plasmon-driven enhancement interband-transition suppression, such competitive effects on PESHG can be readily observed quantitatively measured. Our work may provide insights understanding the physical mechanism governing optical help attain efficient wavelength conversions quantum-optical metamaterial applications.