Subjects

Abstract

Understanding how light interacts with matter at the nanometre scale is a fundamental issue in optoelectronics and nanophotonics. In particular, many applications (such as bio-sensing, cancer therapy and all-optical signal processing) rely on surface-bound optical excitations in metallic nanoparticles. However, so far no experimental technique has been capable of imaging localized optical excitations with sufficient resolution to reveal their dramatic spatial variation over one single nanoparticle. Here, we present a novel method applied on silver nanotriangles, achieving such resolution by recording maps of plasmons in the near-infrared/visible/ultraviolet domain using electron beams instead of photons. This method relies on the detection of plasmons as resonance peaks in the energy-loss spectra of subnanometre electron beams rastered on nanoparticles of well-defined geometrical parameters. This represents a significant improvement in the spatial resolution with which plasmonic modes can be imaged, and provides a powerful tool in the development of nanometre-level optics.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    , & Synthesis and optical properties of anisotropic metal nanoparticles. J. Fluoresc. 14, 331–341 (2004).

  2. 2.

    et al. Squeezing the optical near-field zone by plasmon coupling of metallic nanoparticles. Phys. Rev. Lett. 82, 2590–2593 (1999).

  3. 3.

    , , , & Localized surface plasmon resonance spectroscopy of single silver triangular nanoprisms. Nano Lett. 6, 2060–2065 (2006).

  4. 4.

    Plasma losses by fast electrons in thin films. Phys. Rev. 106, 874–881 (1957).

  5. 5.

    , & Electron-energy losses in silicon: Bulk and surface plasmons and C˜erenkov radiation. Phys. Rev. B 12, 64–71 (1973).

  6. 6.

    Surface Plasmons on Smooth and Rough Surfaces and on Gratings (Springer Tracts in Modern Physics, Vol. 111, Springer, Berlin, 1988).

  7. 7.

    & Generation of surface excitations on dielectric spheres by an external elctron-beam. Phys. Rev. Lett. 55, 1526–1529 (1985).

  8. 8.

    Relativistic energy loss and induced photon emission in the interaction of a dielectric sphere with an external electron beam. Phys. Rev. B 59, 3095–3107 (1999).

  9. 9.

    Surface plasmon coupling in clusters of small spheres. Phys. Rev. Lett. 49, 936–940 (1982).

  10. 10.

    , & Surface-plasmon and interface-plasmon modes on small semiconducting spheres. Phys. Rev. B 45, 4332–4343 (1992).

  11. 11.

    et al. Electron energy loss spectroscopy measurement of the optical gaps on individual boron nitride single-walled and multiwalled nanotubes. Phys. Rev. Lett. 95, 127601 (2005).

  12. 12.

    et al. A TEM and electron energy loss spectroscopy (EELS) investigation of active and inactive silver particles for surface enhanced resonance Raman spectroscopy (SERRS). Faraday Discuss. 132, 171–178 (2006).

  13. 13.

    , & Photon emission from silver particles induced by a high-energy electron beam. Phys. Rev. B 6420, 205419 (2001).

  14. 14.

    , , , & Formation of silver nanoprisms with surface plasmons at communication wavelengths. Adv. Funct. Mater. 16, 766–773 (2006).

  15. 15.

    & Spectrum-image: The next step in EELS digital acquisition and processing. Ultramicroscopy 28, 252–257 (1989).

  16. 16.

    , , & Improving energy resolution of EELS spectra: An alternative to the monochromator solution. Ultramicroscopy 96, 385–400 (2003).

  17. 17.

    , & Quantum sizes effects in the surface-plasmon excitation of small metallic particles by electron-energy-loss spectroscopy. Phys. Rev. B 46, 15421–15425 (1992).

  18. 18.

    , , & The optical properties of metal nanoparticles: The influence of size, shape, and dielectric environment. J. Phys. Chem. B 107, 668–677 (2003).

  19. 19.

    , , , & Probing surface plasmons on individual nano-objects by near-field electron energy loss spectroscopy. Proc. SPIE 5927, 592711 (2005).

  20. 20.

    & Electromagnetic fields around silver nanoparticles and dimers. J. Chem. Phys. 120, 357–366 (2004).

  21. 21.

    & Relativistic electron energy loss and electron-induced photon emission in lymphogenous dielectrics. Phys. Rev. Lett. 80, 5180–5183 (1998).

  22. 22.

    & Retarded field calculation of electron energy loss in inhomogeneous dielectrics. Phys. Rev. B 65, 115418 (2002).

  23. 23.

    & Optical constants of the noble metals. Phys. Rev. B 6, 4370 (1972).

  24. 24.

    On the properties of a gas of charged particles. K. Dan. Vidensk. Selsk. Mat.-Fys. Medd. 28, 1–57 (1954).

  25. 25.

    et al. Cherenkov effect as a probe of photonic nanostructures. Phys. Rev. Lett. 91, 143902 (2003).

  26. 26.

    , & Theoretical principles of near-field optical microscopies and spectroscopies. J. Chem. Phys. 112, 7775–7789 (2000).

  27. 27.

    , , & Definition and measurement of the local density of electromagnetic states close to an interface. Phys. Rev. B 68, 245405 (2003).

  28. 28.

    & Delocalization in inelastic-scattering. Ultramicroscopy 59, 195–213 (1995).

Download references

Acknowledgements

This work was partially supported by the Centre National de la Recherche Scientifique (CNRS) through the ACN NR131, the Spanish Ministerio de Educaciø´n y Ciencia (Project No. MAT2004-02991) and the EU project No. STRP-016881-SPANS. L.H. is supported by the Belgian FNRS and the Belgian interuniversity project PAI-IUAP 5/01.

Author information

Affiliations

  1. Laboratoire de Physique des Solides, Bâtiment 510, CNRS UMR 8502, Université Paris Sud XI, F 91405 Orsay, France

    • Jaysen Nelayah
    • , Mathieu Kociak
    • , Odile Stéphan
    • , Marcel Tencé
    • , Dario Taverna
    •  & Christian Colliex
  2. Instituto de Optica, CSIC, Serrano 121, 28006 Madrid, Spain

    • F. Javier García de Abajo
  3. Laboratoire de Physique du Solide, Facultés Universitaires Notre Dame de la Paix, Namur B-5000, Belgium

    • Luc Henrard
  4. Departamento de Química Física, Universidade de Vigo, 36310 Vigo, Spain

    • Isabel Pastoriza-Santos
    •  & Luis M. Liz-Marzán

Authors

  1. Search for Jaysen Nelayah in:

  2. Search for Mathieu Kociak in:

  3. Search for Odile Stéphan in:

  4. Search for F. Javier García de Abajo in:

  5. Search for Marcel Tencé in:

  6. Search for Luc Henrard in:

  7. Search for Dario Taverna in:

  8. Search for Isabel Pastoriza-Santos in:

  9. Search for Luis M. Liz-Marzán in:

  10. Search for Christian Colliex in:

Contributions

This is a collective study in which members at (1) have mostly carried out experiments and measurements, members at (2) and (3) have mostly contributed to modelling and members at (4) have been responsible for the synthesis of the Ag nanoprisms.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Odile Stéphan.

Supplementary information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nphys575

Further reading