TY - JOUR
T1 - Scaling the Artificial Polariton Bandgap at Infrared Frequencies Using Indium Tin Oxide Nanorod Arrays
AU - Chen, Xiangfan
AU - Guo, Peijun
AU - He, Cheng
AU - Dong, Biqin
AU - Ocola, Leonidas E.
AU - Schaller, Richard D.
AU - Chang, Robert P.H.
AU - Sun, Cheng
N1 - Publisher Copyright:
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2016/12/1
Y1 - 2016/12/1
N2 - 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.
AB - 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.
KW - electric dipole coupling
KW - indium tin oxide nanorod arrays
KW - infrared
KW - plasmon–polariton bandgaps
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U2 - 10.1002/adom.201600439
DO - 10.1002/adom.201600439
M3 - Article
AN - SCOPUS:84988353628
SN - 2195-1071
VL - 4
SP - 2077
EP - 2084
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 12
ER -