Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Demonstration of a spaser-based nanolaser


One of the most rapidly growing areas of physics and nanotechnology focuses on plasmonic effects on the nanometre scale, with possible applications ranging from sensing and biomedicine to imaging and information technology1,2. However, the full development of nanoplasmonics is hindered by the lack of devices that can generate coherent plasmonic fields. It has been proposed3 that in the same way as a laser generates stimulated emission of coherent photons, a ‘spaser’ could generate stimulated emission of surface plasmons (oscillations of free electrons in metallic nanostructures) in resonating metallic nanostructures adjacent to a gain medium. But attempts to realize a spaser face the challenge of absorption loss in metal, which is particularly strong at optical frequencies. The suggestion4,5,6 to compensate loss by optical gain in localized and propagating surface plasmons has been implemented recently7,8,9,10 and even allowed the amplification of propagating surface plasmons in open paths11. Still, these experiments and the reported enhancement of the stimulated emission of dye molecules in the presence of metallic nanoparticles12,13,14 lack the feedback mechanism present in a spaser. Here we show that 44-nm-diameter nanoparticles with a gold core and dye-doped silica shell allow us to completely overcome the loss of localized surface plasmons by gain and realize a spaser. And in accord with the notion that only surface plasmon resonances are capable of squeezing optical frequency oscillations into a nanoscopic cavity to enable a true nanolaser15,16,17,18, we show that outcoupling of surface plasmon oscillations to photonic modes at a wavelength of 531 nm makes our system the smallest nanolaser reported to date—and to our knowledge the first operating at visible wavelengths. We anticipate that now it has been realized experimentally, the spaser will advance our fundamental understanding of nanoplasmonics and the development of practical applications.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: Spaser design.
Figure 2: Spectroscopic results.
Figure 3: Emission kinetics.
Figure 4: Stimulated emission.


  1. Maier, S. A. Plasmonics: Fundamentals and Applications (Springer, 2007)

    Book  Google Scholar 

  2. Brongersma, M. L. & Kik, P. G. Surface Plasmon Nanophotonics (Springer Series in Optical Sciences, Vol. 131, Springer, 2007)

  3. Bergman, D. J. & Stockman, M. I. Surface plasmon amplification by stimulated emission of radiation: quantum generation of coherent surface plasmons in nanosystems. Phys. Rev. Lett. 90, 027402 (2003)

    Article  ADS  Google Scholar 

  4. Sudarkin, A. N. & Demkovich, P. A. Excitation of surface electromagnetic waves on the boundary of a metal with an amplifying medium. Sov. Phys. Tech. Phys. 34, 764–766 (1989)

    Google Scholar 

  5. Nezhad, M. P., Tetz, K. & Fainman, Y. Gain assisted propagation of surface plasmon on planar metallic waveguides. Opt. Express 12, 4072–4079 (2004)

    Article  ADS  Google Scholar 

  6. Lawandy, N. M. Localized surface plasmon singularities in amplifying media. Appl. Phys. Lett. 85, 5040–5042 (2004)

    Article  ADS  CAS  Google Scholar 

  7. Noginov, M. A. et al. Enhancement of surface plasmons in an Ag aggregate by optical gain in a dielectric medium. Opt. Lett. 31, 3022–3024 (2006)

    Article  ADS  CAS  Google Scholar 

  8. Noginov, M. A. et al. The effect of gain and absorption on surface plasmons in metal nanoparticles. Appl. Phys. B 86, 455–460 (2007)

    Article  ADS  CAS  Google Scholar 

  9. Seidel, J., Grafstroem, S. & Eng, L. Stimulated emission of surface plasmons at the interface between a silver film and an optically pumped dye solution. Phys. Rev. Lett. 94, 177401 (2005)

    Article  ADS  CAS  Google Scholar 

  10. Noginov, M. A. et al. Compensation of loss in propagating surface plasmon polariton by gain in adjacent dielectric medium. Opt. Express 16, 1385–1392 (2008)

    Article  ADS  CAS  Google Scholar 

  11. Noginov, M. A. et al. Stimulated emission of surface plasmon polaritons. Phys. Rev. Lett. 101, 226806 (2008)

    Article  ADS  CAS  Google Scholar 

  12. Dice, G. D., Mujumdar, S. & Elezzabi, A. Y. Plasmonically enhanced diffusive and subdiffusive metal nanoparticle-dye random laser. Appl. Phys. Lett. 86, 131105 (2005)

    Article  ADS  Google Scholar 

  13. Popov, O., Zilbershtein, A. & Davidov, D. Random lasing from dye-gold nanoparticles in polymer films: enhanced gain at the surface-plasmon-resonance wavelength. Appl. Phys. Lett. 89, 191116 (2006)

    Article  ADS  Google Scholar 

  14. Kawasaki, M. & Mine, S. Novel lasing action in dye-doped polymer films coated on large pseudotabular Ag islands. J. Phys. Chem. B 110, 15052–15054 (2006)

    Article  CAS  Google Scholar 

  15. Muhlschlegel, P., Eisler, H.-J., Martin, O. J. F., Hecht, B. & Phol, D. W. Resonant optical antennas. Science 308, 1607–1609 (2005)

    Article  ADS  CAS  Google Scholar 

  16. Gordon, J. A. & Ziolkowski, R. W. The design and simulated performance of a coated nanoparticle laser. Opt. Express 15, 2622–2653 (2007)

    Article  ADS  CAS  Google Scholar 

  17. Noda, S. Seeking the ultimate nanolaser. Science 314, 260–261 (2006)

    Article  CAS  Google Scholar 

  18. Hill, M. T. et al. Lasing in metallic-coated nanocavities. Nature Photon. 1, 563–564 (2007)

    Article  Google Scholar 

  19. Enüstün, B. V. & Turkevich, J. Coagulation of colloidal gold. J. Am. Chem. Soc. 85, 3317–3328 (1963)

    Article  Google Scholar 

  20. Ow, H. et al. Bright and stable core-shell fluorescent silica nanoparticles. Nano Lett. 5, 113–117 (2005)

    Article  ADS  CAS  Google Scholar 

  21. Noginov, M. A. et al. Crystal growth and characterization of a new laser material, Nd:Ba5(PO4)3Cl. J. Opt. Soc. Am. B 17, 1329–1334 (2000)

    Article  ADS  CAS  Google Scholar 

  22. Purcell, E. M. Spontaneous emission probabilities at radio frequencies. Phys. Rev. 69, 681 (1946)

    Article  Google Scholar 

  23. Noginov, M. A., Fowlkes, I., Zhu, G. & Novak, J. Neodymium random lasers operating in different pumping regimes. J. Mod. Opt. 51, 2543–2553 (2004)

    Article  ADS  CAS  Google Scholar 

  24. Svelto, O. Principles of Lasers 4th edn (Plenum, 1998)

    Book  Google Scholar 

  25. Zheludev, N. I., Prosvirnin, S. L., Papasimakis, N. & Fedotov, V. A. Lasing spaser. Nature Photon. 2, 351–354 (2008)

    Article  ADS  CAS  Google Scholar 

  26. Sirtori, C. et al. Long-wavelength (λ ≈ 8–11.5 μm) semiconductor lasers with waveguides based on surface plasmons. Opt. Lett. 23, 1366–1368 (1998)

    Article  ADS  CAS  Google Scholar 

  27. Mulvaney, P., Liz-Marzan, L. M., Giersig, M. & Ung, T. Silica encapsulation of quantum dots and metal clusters. J. Mater. Chem. 10, 1259–1270 (2000)

    Article  CAS  Google Scholar 

  28. Johnson, P. B. & Christy, R. W. Optical constants of the noble metals. Phys. Rev. B 6, 4370–4379 (1972)

    Article  ADS  CAS  Google Scholar 

  29. Born, M. & Wolf, E. Principles of Optics 6th edn (Cambridge Univ. Press, 1998)

    Google Scholar 

  30. Landau, L. D. & Lifshits, E. M. Quantum Mechanics: Non-Relativistic Theory (Pergamon, 1977)

    Google Scholar 

Download references


The work was supported by NSF PREM grant DMR 0611430, NSF NCN (EEC-0228390), NASA URC (NCC3-1035), an ARO-MURI award (50342-PH-MUR) and a United States Army award (W911NF-06-C-0124). We thank M. I. Stockman for discussions, and J. Chen and J. Irudayaraj for the assistance with the kinetics measurements. S.S. was a member of the Summer Research Program at the Center for Materials Research, Norfolk State University.

Author information

Authors and Affiliations


Corresponding author

Correspondence to M. A. Noginov.

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Noginov, M., Zhu, G., Belgrave, A. et al. Demonstration of a spaser-based nanolaser. Nature 460, 1110–1112 (2009).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing