Scaling the Artificial Polariton Bandgap at Infrared Frequencies Using Indium Tin Oxide Nanorod Arrays

Xiangfan Chen, Peijun Guo, Cheng He, Biqin Dong, Leonidas E. Ocola, Richard D. Schaller, Robert P.H. Chang, Cheng Sun

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

Artificial polariton bandgaps at infrared frequencies are investigated by exploiting the strong coupling of electromagnetic waves with induced electric dipoles in two-dimensional (2D) indium tin oxide nanorod arrays (ITO-NRAs). The electric dipoles originate from the collective oscillations of free electrons within the individual ITO nanorods undergoing plasmonic resonance. Controlling the near-field interactions among the neighboring electric dipoles allows for manipulation of the collective polariton modes that are manifested as a polariton bandgap. A theoretical model is developed to understand the coupled phenomena underlying the unique characteristics of plasmon–polariton bandgaps. With high-degree geometric control of the ITO-NRAs, it is experimentally demonstrated that reducing the spacing between ITO nanorods in a square array strengthens the near-field interactions and thus results in a redshift as well as broadening of the polariton bandgap. Furthermore, arranging ITO-NRAs in a rectangular lattice breaks the symmetry with respect to the principle axis, which leads to a splitting of the collective polariton modes owing to the competition between the quasi-longitudinally and quasi-transversely coupled plasmon–polariton modes. The work highlights the use of a classical dipole coupling method for scaling polariton bandgaps to the infrared in artificial plasmonic lattices, thereby offering a new design dimension for infrared sensing, absorbers, and optical communications.

Original languageEnglish (US)
Pages (from-to)2077-2084
Number of pages8
JournalAdvanced Optical Materials
Volume4
Issue number12
DOIs
StatePublished - Dec 1 2016
Externally publishedYes

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Keywords

  • electric dipole coupling
  • indium tin oxide nanorod arrays
  • infrared
  • plasmon–polariton bandgaps

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics

Cite this

Chen, X., Guo, P., He, C., Dong, B., Ocola, L. E., Schaller, R. D., Chang, R. P. H., & Sun, C. (2016). Scaling the Artificial Polariton Bandgap at Infrared Frequencies Using Indium Tin Oxide Nanorod Arrays. Advanced Optical Materials, 4(12), 2077-2084. https://doi.org/10.1002/adom.201600439