Fano resonances with a high figure of merit in silver oligomer systems
A silver quadrumer consisting of four parallel aligned rectangular nanobars, with three at the bottom and one at the top, is proposed to provide two Fano resonances. These two resonances can be adjusted either simultaneously or independently simply by tuning the geometrical parameters. Due to the formation of the two resonances in a relatively short wavelength range, one of them can be spectrally squeezed to be very narrow, which induces a very high figure of merit (FoM=45). By decomposing the scattering spectrum into bright modes and dark modes, the double Fano resonances are found to be originated from grouping the unit cells into two different groups. The evolution of the scattering spectrum with the central dimer position along the polarization direction suggests that the symmetry reducing induces the second Fano resonance and improves the FoM of the first one. By introducing one more nanobar into the quadrumer system, the FoM can approach the material’s limit, although the dip is relatively shallow. The ultrahigh FoM of the Fano resonance in the proposed quadrumer can provide ultra-sensitive refractive index sensing. Furthermore, the method for providing multiple independently tunable Fano resonances can offer new solutions to designing plasmonic-related nanolasers, photocatalysis, and biochemical sensors, etc.
基金项目：National Natural Science Foundation of China (NSFC)10.13039/501100001809 (61675070, 61378082, 11704133).
Fan-Wei Zhang：Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China
Guo-Zhou Li：Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China
Jun-Yi Chen：Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China
Qiang Li：Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China
Li-Jun Wu：Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, ChinaState Key Laboratory of Optoelectric Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
【1】C. Wu, A. B. Khanikaev, R. Adato, N. Arju, A. A. Yanik, H. Altug, and G. Shvets, “Fano-resonant asymmetric metamaterials for ultrasensitive spectroscopy and identification of molecular monolayers,” Nat. Mater. 11 , 69–75 (2012).
【2】Z. L. Deng, N. Yogesh, X. D. Chen, W. J. Chen, J. W. Dong, Z. B. Ouyang, and G. P. Wang, “Full controlling of Fano resonances in metal-slit superlattice,” Sci. Rep. 5 , 18461 (2015).
【3】A. N. Poddubny, M. V. Rybin, M. F. Limonov, and Y. S. Kivshar, “Fano interference governs wave transport in disordered systems,” Nat. Commun. 3 , 914 (2012).
【4】J. A. Fan, K. Bao, C. Wu, J. Bao, R. Bardhan, N. J. Halas, V. N. Manoharan, G. Shvets, P. Nordler, and F. Capasso, “Fano-like interference in self-assembled plasmonic quadrumer clusters,” Nano Lett. 10 , 4680–4685 (2010).
【5】H. X. Xu, E. J. Bjerneld, M. K?ll, and L. Borjesson, “Spectroscopy of single hemoglobin molecules by surface enhanced Raman scattering,” Phys. Rev. Lett. 83 , 4357–4360 (1999).
【6】P. Mühlschlegel, H. J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science 308 , 1607–1609 (2005).
【7】J. N. Anker, W. P. Hall, O. Lyres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7 , 442–453 (2008).
【8】K. M. Mayer, and J. H. Hafner, “Localized surface plasmon resonance sensors,” Chem. Rev. 111 , 3828–3857 (2011).
【9】Y. Shen, J. Zhou, T. Liu, Y. Tao, R. Jiang, M. Liu, G. Xiao, J. Zhu, Z.-K. Zhou, X. Wang, C. Jin, and J. Wang, “Plasmonic gold mushroom arrays with refractive index sensing figures of merit approaching the theoretical limit,” Nat. Commun. 4 , 2381 (2013).
【10】S. Mukherjee, F. Libisch, N. Large, O. Neumann, L. V. Brown, J. Cheng, J. B. Lassiter, E. A. Carter, P. Nordlander, and N. J. Halas, “Hot electrons do the impossible: plasmon-induced dissociation of H2 on Au,” Nano Lett. 13 , 240–247 (2013).
【11】S. Biswas, J. Duan, D. Nepal, K. Park, R. Pachter, and R. A. Vaia, “Plasmonic resonances in self-assembled reduced symmetry gold nanorod structures,” Nano Lett. 13 , 6287–6291 (2013).
【12】A. Ahmadiv, M. Karabiyik, and N. Pala, “Intensifying magnetic dark modes in the antisymmetric plasmonic quadrumer composed of AL/Al2O3 nanodisks with the placement of silicon nanospheres,” Opt. Commun. 338 , 218–225 (2015).
【13】F. Hao, P. Nordlander, Y. Sonnefraud, P. V. Dorpe, and S. A. Maier, “Tunability of subradiant dipolar and Fano-type plasmon resonances in metallic ring/disk cavities: implications for nanoscale optical sensing,” ACS Nano 3 , 643–652 (2009).
【14】F. Neubrech, A. Pucci, T. Walter Cornelius, S. Karim, A. Garcia-Etxarri, and J. Aizpurua, “Resonant plasmonic and vibrational coupling in a tailored nanoantenna for infrared detection,” Phys. Rev. Lett. 101 , 157403 (2008).
【15】H. Aouani, H. ?ípová, M. Rahmani, M. Navarro-Cia, K. Hegnerová, J. Homola, M. Hong, and S. A. Maier, “Ultrasensitive broadband probing of molecular vibrational modes with multifrequency optical antennas,” ACS Nano 7 , 669–675 (2012).
【16】B. Gallinet, and O. J. F. Martin, “Influence of electromagnetic interactions on the line shape of plasmonic Fano resonances,” ACS Nano 5 , 8999–9008 (2011).
【17】J. A. Fan, Y. He, K. Bao, C. Wu, J. Bao, N. B. Schade, V. N. Manoharan, G. Shvets, P. Nordler, D. R. Liu, and F. Capasso, “DNA-enabled self-assembly of plasmonic nanoclusters,” Nano Lett. 11 , 4859–4864 (2011).
【18】F. Wang, and Y. R. Shen, “General properties of local plasmons in metal nanostructures,” Phys. Rev. Lett. 97 , 206806 (2006).
【19】L. V. Brown, H. Sobhani, J. B. Lassiter, P. Nordlander, and N. J. Halas, “Heterodimers: plasmonic properties of mismatched nanoparticle pairs,” ACS Nano 4 , 819–832 (2010).
【20】Z. J. Yang, Z. S. Zhang, W. Zhang, Z. H. Hao, and Q. Q. Wang, “Twinned Fano interferences induced by hybridized plasmons in Au-Ag nanorod heterodimers,” Appl. Phys. Lett. 96 , 13113 (2010).
【21】A. Lovera, B. Gallinet, P. Nordlander, and O. J. F. Martin, “Mechanisms of Fano resonances in coupled plasmonic systems,” ACS Nano 7 , 4527–4536 (2013).
【22】N. Verellen, Y. Sonnefraud, H. Sobhani, F. Hao, V. V. Moshchalkov, P. V. Dorpe, P. Nordlander, and S. A. Maier, “Fano resonances in individual coherent plasmonic nanocavities,” Nano Lett. 9 , 1663–1667 (2009).
【23】F. Hao, Y. Sonnefraud, P. V. Dorpe, S. A. Maier, N. J. Halas, and P. Nordler, “Symmetry breaking in plasmonic nanocavities: subradiant LSPR sensing and a tunable Fano resonance,” Nano Lett. 8 , 3983–3988 (2008).
【24】S. P. Zhang, and H. X. Xu, “Tunable dark plasmons in a metallic nanocube dimer toward ultimate sensitivity nanoplasmonic sensors,” Nanoscale 8 , 13722–13729 (2016).
【25】J. Chen, Q. Shen, Z. Chen, Q. Wang, C. Tang, and Z. Wang, “Multiple Fano resonances in monolayer hexagonal non-close-packed metallic shells,” J. Chem. Phys. 136 , 214703 (2012).
【26】D. Dregely, M. Hentschel, and H. Giessen, “Excitation and tuning of higher-order Fano resonances in plasmonic oligomer clusters,” ACS Nano 5 , 8202–8211 (2011).
【27】Y. Cui, J. Zhou, V. A. Tamma, and W. Park, “Dynamic tuning and symmetry lowering of Fano resonance in plasmonic nanostructure,” ACS Nano 6 , 2385–2393 (2012).
【28】S. D. Liu, Z. Yang, R. P. Liu, and X. Y. Li, “Multiple Fano resonances in plasmonic heptamer clusters composed of split nanorings,” ACS Nano 6 , 6260–6271 (2012).
【29】S. D. Liu, Y. B. Yang, Z. H. Chen, W. J. Wang, H. M. Fei, M. J. Zhang, and Y. C. Wang, “Excitation of multiple Fano resonances in plasmonic clusters with D2h point group symmetry,” J. Phys. Chem. C 117 , 14218–14228 (2013).
【30】Y. Wang, Z. Li, K. Zhao, A. Sobhani, X. Zhu, Z. Fang, and N. J. Halas, “Substrate-mediated charge transfer plasmons in simple and complex nanoparticle clusters,” Nanoscale 5 , 9897–9901 (2013).
【31】Z. J. Yang, Q. Q. Wang, and H. Q. Lin, “Tunable two types of Fano resonances in metal-dielectric core-shell nanoparticle clusters,” Appl. Phys. Lett. 103 , 111115 (2013).
【32】J. Zhang, and A. Zayats, “Multiple Fano resonances in single-layer nonconcentric core-shell nanostructures,” Opt. Express 21 , 8426–8436 (2013).
【33】J. Wang, C. Fan, J. He, P. Ding, E. Liang, and Q. Xue, “Double Fano resonances due to interplay of electric and magnetic plasmon modes in planar plasmonic structure with high sensing sensitivity,” Opt. Express 21 , 2236–2244 (2013).
【34】Y. Zhang, T. Q. Jia, H. M. Zhang, and Z. Z. Xu, “Fano resonances in disk-ring plasmonic nanostructure: strong interaction between bright dipolar and dark multipolar mode,” Opt. Lett. 37 , 4919–4921 (2012).
【35】A. D. Khan, S. D. Khan, R. U. Khan, and N. Ahmad, “Excitation of multiple Fano-like resonances induced by higher order plasmon modes in three-layered bimetallic nanoshell dimer,” Plasmonics 9 , 461–475 (2014).
【36】L. Y. Yin, Y. H. Huang, X. Wang, S. T. Ning, and S. D. Liu, “Double Fano resonances in nanoring cavity dimers: the effect of plasmon hybridization between dark subradiant modes,” AIP Adv. 4 , 077113 (2014).
【37】N. Liu, M. Hentschel, T. Weiss, A. P. Alivisatos, and H. Giessen, “Three-dimensional plasmon rulers,” Science 332 , 1407–1410 (2011).
【38】Y. H. Fu, J. B. Zhang, Y. F. Yu, and B. Luk’yanchuk, “Generating and manipulating higher order Fano resonances in dual-disk ring plasmonic nanostructures,” ACS Nano 6 , 5130–5137 (2012).
【39】A. Artar, A. A. Yanik, and H. Altug, “Directional double Fano resonances in plasmonic hetero-oligomers,” Nano Lett. 11 , 3694–3700 (2011).
【40】M. Hentschel, D. Dregely, R. Vogelgesang, H. Giessen, and N. Liu, “Plasmonic oligomers: the role of individual particles in collective behavior,” ACS Nano 5 , 2042–2050 (2011).
【41】C. Wu, A. B. Khanikaev, and G. Shvets, “Broadband slow light metamaterial based on a double-continuum Fano resonance,” Phys. Rev. Lett. 106 , 107403 (2011).
【42】G. Z. Li, Q. Li, L. Xu, and L. J. Wu, “Double Fano resonances in plasmonic nanocross molecules and magnetic plasmon propagation,” Nanoscale 7 , 19914–19920 (2015).
【43】P. B. Johnson, and R. W. Christy, “Optical-constants of noble-metals,” Phys. Rev. B 6 , 4370–4379 (1972).
【44】S. Fan, W. Suh, and J. D. Joannopoulos, “Temporal coupled-mode theory for the Fano resonance in optical resonators,” J. Opt. Soc. Am. A 20 , 569–572 (2003).
【45】Z. Ruan, and S. Fan, “Temporal coupled-mode theory for Fano resonance in light scattering by a single obstacle,” J. Phys. Chem. C 114 , 7324–7329 (2010).
【46】B. Gallinet, and O. J. F. Martin, “Ab initio theory of Fano resonances in plasmonic nanostructures and metamaterials,” Phys. Rev. B 83 , 235427 (2011).
【47】Y. H. Zhan, D. Y. Lei, X. F. Li, and S. A. Maier, “Plasmonic Fano resonances in nanohole quadrumers for ultra-sensitive refractive index sensing,” Nanoscale 6 , 4705–4715 (2014).
【48】G. Z. Li, Q. Li, L. Xu, and L. J. Wu, “Numerical realization of Fano-type resonances in cascaded plasmonic heterodimers for refractive index sensing,” Plasmonics 10 , 1401–1407 (2015).
【49】J. A. Fan, C. Wu, K. Bao, J. Bao, R. Bardhan, N. Halas, V. Manoharan, P. Nordlander, G. Shvets, and F. Capasso, “Self-assembled plasmonic nanoparticle clusters,” Science 328 , 1135–1138 (2010).
Hong-Jin Hu, Fan-Wei Zhang, Guo-Zhou Li, Jun-Yi Chen, Qiang Li, and Li-Jun Wu, "Fano resonances with a high figure of merit in silver oligomer systems," Photonics Research 6(3), 204-213 (2018)