Polarization-independent multiple fano resonances in plasmonic nonamers for multimode-matching enhanced multiband second-harmonic generation

Shao Ding Liu, Eunice Sok Ping Leong, Guang Can Li, Yidong Hou, Jie Deng, Jing Hua Teng, Hock Chun Ong, Dangyuan Lei

Research output: Journal article publicationJournal articleAcademic researchpeer-review

98 Citations (Scopus)

Abstract

Plasmonic oligomers composed of metallic nanoparticles are one class of the most promising platforms for generating Fano resonances with unprecedented optical properties for enhancing various linear and nonlinear optical processes. For efficient generation of second-harmonic emissions at multiple wavelength bands, it is critical to design a plasmonic oligomer concurrently having multiple Fano resonances spectrally matching the fundamental excitation wavelengths and multiple plasmon resonance modes coinciding with the harmonic wavelengths. Thus far, the realization of such a plasmonic oligomer remains a challenge. This study demonstrates both theoretically and experimentally that a plasmonic nonamer consisting of a gold nanocross surrounded by eight nanorods simultaneously sustains multiple polarization-independent Fano resonances in the near-infrared region and several higher-order plasmon resonances in the visible spectrum. Due to coherent amplification of the nonlinear excitation sources by the Fano resonances and efficient scattering-enhanced outcoupling by the higher-order modes, the second-harmonic emission of the nonamer is significantly increased at multiple spectral bands, and their spectral positions and radiation patterns can be flexibly manipulated by easily tuning the length of the surrounding nanorods in the nonamer. These results provide us with important implications for realizing ultrafast multichannel nonlinear optoelectronic devices.
Original languageEnglish
Pages (from-to)1442-1453
Number of pages12
JournalACS Nano
Volume10
Issue number1
DOIs
Publication statusPublished - 26 Jan 2016

Keywords

  • Fano resonances
  • Higher-order plasmon modes
  • Metallic nanostructures
  • Plasmonic oligomers
  • Second-harmonic generation

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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