, Volume 13, Issue 6, pp 1861–1865 | Cite as

Coated Drop-Shaped Nanowires for Guiding THz Surface Plasmon Polaritons with Nanoscale Confinement and Ultra-Long Propagation Distances

  • Hui Yin
  • Xuan Cong
  • Min Zhang
  • Hong Su
  • Ireng Ling LiEmail author
  • Huawei LiangEmail author


Focusing far beyond the diffraction limit is very important for terahertz (THz) wave applications due to its much longer wavelength compared with optical wave. Surface plasmon polaritons (SPPs) on metal wires are frequently used to attain this focusing. However, when the mode width is reduced down to the nanometer scale, the mode loss is very high. Here, a coated drop-shaped nanowire (CDSN) is proposed for guiding THz SPPs with both ultra-strong mode confinement (10 nm) and extreme-long propagation length (1~15 mm), which result from the distinctive mode fields around the top and bottom arcs, respectively, of the metal wire. The fantastic mode properties make the waveguide very useful in nanophotonics, bio-photonics, and highly integrated photonic circuits.


THz wave Surface plasmon polaritons THz waveguides Metal nanowires 


Funding Information

This work was supported in part by the National Natural Science Foundation of China under Grant 61405124, and the Fund Project for Shenzhen Fundamental Research Programme, China under Grant JCYJ20160308092830132.


  1. 1.
    Mittleman DM (2002) Sensing with terahertz radiation. Springer, HeidelbergGoogle Scholar
  2. 2.
    Kawase K, Ogawa Y, Watanabe Y, Inoue H (2003) Non-destructive terahertz imaging of illicit drugs using spectral fingerprints. Opt Express 11(20):2549. CrossRefPubMedGoogle Scholar
  3. 3.
    Fitch MJ, Osiander R (2004) Terahertz waves for communications and sensing. Johns Hopkins Apl Technical Digest 25:348–355Google Scholar
  4. 4.
    Wang K, Mittleman DM (2004) Metal wires for terahertz wave guiding. Nature 432(7015):376–379. CrossRefPubMedGoogle Scholar
  5. 5.
    Cao Q, Jahns J (2005) Azimuthally polarized surface plasmons as effective terahertz waveguides. Opt Express 13(2):511–518. CrossRefPubMedGoogle Scholar
  6. 6.
    Walther M, Freeman MR, Hegmann FA (2005) Metal-wire terahertz time-domain spectroscopy. Appl Phys Lett 87:42CrossRefGoogle Scholar
  7. 7.
    Valk NCJVD, Planken PCM (2005) Effect of a dielectric coating on terahertz surface plasmon polaritons on metal wires. Appl Phys Lett 87(7):–071106. CrossRefGoogle Scholar
  8. 8.
    Gacemi D, Mangeney J, Laurtent T, Lampin J-F, Akalin T, Blary K, Degiron A, Crozat P, Meng F (2012) THz surface plasmon modes on planar Goubau lines. Opt Express 20(8):8466–8471. CrossRefPubMedGoogle Scholar
  9. 9.
    Maier SA, Andrews SR, Martín-Moreno L, García-Vidal FJ (2006) Terahertz surface plasmon-polariton propagation and focusing on periodically corrugated metal wires. Phys Rev Lett 97(17):176805. CrossRefPubMedGoogle Scholar
  10. 10.
    Liang H, Ruan S, Zhang M (2008) Terahertz surface wave propagation and focusing on conical metal wires. Opt Express 16:18241–18248CrossRefPubMedGoogle Scholar
  11. 11.
    Astley V, Mendis R, Mittleman DM (2009) Characterization of terahertz field confinement at the end of a tapered metal wire waveguide. Appl Phys Lett 95:031104CrossRefGoogle Scholar
  12. 12.
    Awad M, Nagel M, Kurz H (2009) Tapered Sommerfeld wire terahertz near-field imaging. Appl Phys Lett 94:2128CrossRefGoogle Scholar
  13. 13.
    Zhan H, Mendis R, Mittleman DM (2010) Superfocusing terahertz waves below λ/250 using plasmonic paralle-plate waveguides. Opt Express 18:9643–9650CrossRefPubMedGoogle Scholar
  14. 14.
    Liang H, Ruan S, Zhang M, Su H (2010) Nanofocusing of terahertz wave on conical metal wire waveguides. Opt Commun 283(2):262–264. CrossRefGoogle Scholar
  15. 15.
    Yang J, Cao Q, Zhou C (2010) Theory for terahertz plasmons of metallic nanowires with sub-skin-depth diameters. Opt Express 18:18550–18557CrossRefPubMedGoogle Scholar
  16. 16.
    He X (2010) Investigation of terahertz surface waves of a metallic nanowire. J Opt Soc Am B 27(11):2298–2303. CrossRefGoogle Scholar
  17. 17.
    Huang Y, Zhang L, Yin H, Zhang M, Su H, Li IL, Liang H (2017) Graphene-coated nanowires with a drop-shaped cross section for 10 nm confinement and 1 mm propagation. Opt Lett 42(11):2078–2081. CrossRefPubMedGoogle Scholar
  18. 18.
    Disfani MR, Abrishamian MS, Berini P (2012) Teardrop-shaped surface-plasmon resonators. Opt Express 20(6):6472–6477. CrossRefPubMedGoogle Scholar
  19. 19.
    Long LL, Ordal MA, Querry MR et al (1985) Optical properties of fourteen metals in the infrared and far infrared: Al, Co, Cu, Au, Fe, Pb, Mo, Ni, Pd, Pt, Ag, Ti, V, and W. Appl Opt 24:4493CrossRefPubMedGoogle Scholar
  20. 20.
    Huang Y, Zhang M, Li IL, Yin H, Liang H (2016) Nano-scale THz wave propagation with ultra-low loss. Plasmonics 12:1947–1951CrossRefGoogle Scholar
  21. 21.
    Birch JR (1990) The far infrared optical constants of polyethylene. Infrared Phys 30(2):195–197. CrossRefGoogle Scholar

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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Shenzhen Key Laboratory of Laser EngineeringShenzhen UniversityShenzhenChina
  2. 2.Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceShenzhen UniversityShenzhenChina

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