-
Abstract
We propose a coupling model to describe the interaction between the bright and dark modes of the plasmons of a dimer composed of two orthogonal gold nano-rods (GNRs), referred to as the BDMC model. This model shows that the eigen-frequencies of the coupled plasmons are governed by Coulomb potential and electrostatic potential. With the BDMC model, the behaviors of the coupling coefficient and the frequency offset, which is a new parameter introduced here, are revealed. Meanwhile, the asymmetric behavior of two eigen-frequencies related to gap of two GNRs is explained. Using the harmonic oscillator model and the coupled parameters obtained by the BDMC model, the bright mode absorption spectra of the dimer are calculated and the results agree with the numerical simulation. -
-
References
[1] Zhang S et al. 2008 Phys. Rev. Lett. 101 047401 doi: 10.1103/PhysRevLett.101.047401}[2] Andrey E M et al. 2010 Rev. Mod. Phys. 82 2257 doi: 10.1103/RevModPhys.82.2257}[3] Hao F et al. 2008 Nano Lett. 8 3983 doi: 10.1021/nl802509r}[4] Dong Z G et al. 2010 Appl. Phys. Lett. 97 114101 doi: 10.1063/1.3488020}[5] Hokari R et al. 2014 J. Opt. Soc. Am. B 31 1000 doi: 10.1364/JOSAB.31.001000}[6] Kekatpure R D et al. 2010 Phys. Rev. Lett. 104 243902 doi: 10.1103/PhysRevLett.104.243902}[7] Wang G et al. 2012 Opt. Express 20 20902 doi: 10.1364/OE.20.020902}[8] Yang Z J et al. 2011 Opt. Lett. 36 1542 doi: 10.1364/OL.36.001542}[9] Luk'yanchuk B et al. 2010 Nat. Mater. 9 707 doi: 10.1038/nmat2810}[10] Mukherjee S et al. 2010 Nano Lett. 10 2694 doi: 10.1021/nl1016392}[11] Zhang S et al. 2016 ACS Nano 10 11105 doi: 10.1021/acsnano.6b05979}[12] Liu N et al. 2009 Nat. Mater. 8 758 doi: 10.1038/nmat2495}[13] Cui C et al. 2018 ACS Photon. 5 4074 doi: 10.1021/acsphotonics.8b00754}[14] Ai B et al. 2018 J. Phys. Chem. C 122 20935 doi: 10.1021/acs.jpcc.8b05154}[15] Dong Z G et al. 2010 Opt. Express 18 18229 doi: 10.1364/OE.18.018229}[16] Tian Y et al. 2017 Opt. Eng. 56 107106 doi: 10.1117/1.OE.56.10.107106}[17] Xia S X et al. 2016 Opt. Express 24 17886 doi: 10.1364/OE.24.017886}[18] Vafapour Z and Alaei H 2017 Plasmonics 12 479 doi: 10.1007/s11468-016-0288-0}[19] Stete F et al. 2017 AfCS Photon. 4 1669 doi: 10.1021/acsphotonics.7b00113}[20] Lee S et al. 2018 Opt. Express 26 21537 doi: 10.1364/OE.26.021537}[21] Bakhti S et al. 2016 Sci. Rep. 6 32061 doi: 10.1038/srep32061}[22] Yin S et al. 2015 Sci. Rep. 5 16440 doi: 10.1038/srep16440}[23] Sarkar M et al. 2015 Opt. Express 23 27376 doi: 10.1364/OE.23.027376}[24] Garrido Alzar C L et al. 2002 Am. J. Phys. 70 37 doi: 10.1119/1.1412644}[25] Novotny L 2010 Am. J. Phys. 78 1199 doi: 10.1119/1.3471177}[26] Lovera A et al. 2013 ACS Nano 7 4527 doi: 10.1021/nn401175j}[27] Cheng H et al. 2013 Appl. Phys. Lett. 103 203112 doi: 10.1063/1.4831776}[28] Zuloaga J and Nordlander P 2011 Nano Lett. 11 1280 doi: 10.1021/nl1043242}[29] Lassiter J B et al. 2012 Nano Lett. 12 1058 doi: 10.1021/nl204303d}[30] Davis T J and Gómez D E 2017 Rev. Mod. Phys. 89 011003 doi: 10.1103/RevModPhys.89.011003}[31] Ma P P et al. 2016 Acta Phys. Sin. 65 217801 doi: 10.7498/aps.65.217801}[32] Zhang J et al. 2018 J. Opt. Soc. Am. B 35 1854 doi: 10.1364/JOSAB.35.001854}[33] Johnson P B and Christy R W 1972 Phys. Rev. B 6 4370 doi: 10.1103/PhysRevB.6.4370}[34] Sidorenko S and Martin O J F 2007 Opt. Express 15 6380 doi: 10.1364/OE.15.006380}[35] Berenger J P 1994 J. Comput. Phys. 114 185 doi: 10.1006/jcph.1994.1159}[36] Mittra R and Pekel U 1995 IEEE Microwave Guided Wave Lett. 5 84 doi: 10.1109/75.366461}