Spectrally-Tunable Directionality of Compact Optical Nanoantennas
Tóm tắt
We propose a novel design of plasmonic compact nanoantenna with an efficiently engineered spectral response for the directive emission or harvesting of light. The nanoantenna comprised of four gold nanodisks, arranged longitudinally, and appropriately spaced. Interestingly, by tuning of the inter-particle distances, it is found that the proposed nanoantenna shows either dual-band or broad-band unidirectional performances. These remarkable spectral effects are due to the tailored energies of the two hybridized out-of-phase LSPR modes and the intrinsic electromagnetic interactions. The theoretical predictions are obtained based on the modified coupled-dipole approximation method. In order to obtain more accurate theoretical results, the primary incident optical field seen by the smaller nanodisks are modified by taking into account the field-enhancement caused by the excited plasmons in the largest nanodisk when it is illuminated first. The theoretical results are confirmed by the electromagnetic simulations.
Tài liệu tham khảo
Bharadwaj P, Deutsch B, Novotny L (2009) Optical antennas. Adv Opt Photon 1:438–484
Alu A, Engheta N (2008) Tuning the scattering response of optical nanoantennas with nanocircuit loads. Nat Photon 2:307–310
Curto AG, Volpe G, Taminiau TH, Kreuzer MP, Quidant R, van Hulst NF (2010) Unidirectional emission of a quantum dot coupled to a nanoantenna. Science 329:930–933
Taminiau TH, Moerland RJ, Segerink FB, Kuipers L, van Hulst NF (2007) Resonance of an optical monopole antenna probed by single molecule fluorescence. Nano Lett 7:28–33
Ringler M, Schwemer A, Wunderlich M, Nichtl A, Kürzinger K, Klar TA, Feldmann J (2008) Shaping emission spectra of fluorescent molecules with single plasmonic nanoresonators. Phys Rev Lett 100:203002
Farahani JN, Pohl DW, Eisler HJ, Hecht B (2005) Single quantum dot coupled to a scanning optical antenna: a tunable superemitter. Phys Rev Lett 95:017402
Kühn S, Håkanson U, Rogobete L, Sandoghdar V (2006) Enhancement of single-molecule fluorescence using a gold nanoparticle as an optical nanoantenna. Phys Rev Lett 97:017402
Kinkhabwala A, Yu Z, Fan S, Avlasevich Y, Müllen K, Moerner WE (2009) Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna. Nat Photon 3:654–657
Novotny L, Stranick SJ (2006) Near-field optical microscopy and spectroscopy with pointed probes. Annu Rev Phys Chem 57:303–331
Aizpurua J, Bryant GW, Richter LJ, García de Abajo FJ, Kelley BK, Mallouk T (2005) Optical properties of coupled metallic nanorods for field-enhanced spectroscopy. Phys Rev B 71:235420
Atwater H, Polman A (2010) Plasmonics for improved photovoltaic devices. Nat Mater 9:205
Kühn S, Mori G, Agio M, Sandoghdar V (2008) Modification of single molecule fluorescence close to a nanostructure: radiation pattern, spontaneous emission and quenching. Mol Phys 106:893–908
Tang L, Kocabas SE, Latif S, Okyay AK, Ly-Gagnon DS, Saraswat KC, Miller DAB (2008) Nanometer-scale germanium photodetector enhanced by a near-infrared dipole antenna. Nat Photon 2:226–229
Cao LY, Park JS, Fan PY, Clemens B, Brongersma ML (2010) Resonant germanium nanoantenna photodetectors. Nano Lett 10:1229–1233
Kosako T, Kadoya Y, Hofmann HF (2010) Directional control of light by a nano-optical Yagi–Uda antenna. Nat Photonics 4:312–315
Pakizeh T, Käll M (2009) Unidirectional ultracompact optical nanoantennas. Nano Lett 9:2343–2349
Alavi-Lavasani SH, Pakizeh T (2012) Color-switched ultracompact optical nanoantennas. J Opt Soc Am B 29:1361–1366
Pakizeh T (2012) Unidirectional radiation of a magnetic-dipole coupled to an ultracompact optical nanoantennas. J Opt Soc Am B 29:2446–2452
Dorfmüller J, Dregely D, Eßlinger M, Khunsin W, Vogelgesang R, Kern K, Giessen H (2011) Near-field dynamics of optical Yagi–Uda nanoantennas. Nano Lett 11:2819–2824
Ȕnlȕ ES, Umut Tok R, Șendur K (2011) Broadband plasmonic nanoantenna with an adjustable spectral response. Opt Express 19:1000–1006
Navarro-Cia M, Maier SA (2012) Broad-band near-infrared plasmonic nanoantennas for higher harmonic generation. ACS Nano 6:3537–3544
Shegai T, Miljković VD, Bao K, Xu H, Nordlander P, Johansson P, Käll M (2011) Unidirectional broadband light emission from supported plasmonic nanowire. Nano Lett 11:706–711
Ko KD, Kumar A, Fung KH, Ambekar R, Liu GL, Fang NX, Toussaint KC (2011) Nonlinear optical response from arrays of Au bowtie nanoantennas. Nano Lett 11:61–65
Bohren CF, Huffman DR (1983) Absorption and scattering of light by small particles. Wiley, New York
Pakizeh T, Dmitriev A, Abrishamian MS, Granpayeh N, Käll M (2008) Structural asymmetry and induced optical magnetism in plasmonic nanosandwiches. J Opt Soc Am B 25:659–667
Yang WH, Schatz GC, van Duyne RP (1995) Discrete dipole approximation for calculating extinction and Raman intensities for small particles with arbitrary shapes. J Chem Phys 103:869
Kelly LK, Coronado E, Zhao LL, Schatz GC (2003) The optical properties of metal nanoparticles: the influence of size, shape, and dielectric environment. J Phys Chem B 107:668–677
Born M, Wolf E (1999) Principles of optics. Cambridge University, Cambridge
CST Microwave Studio, http://www.cst.com. Accessed 12 Apr 2010
Johnson PB, Christy RW (1972) Optical constants of the noble metals. Phys Rev B 6:4370–4379