Skip to main content

Thank you for visiting nature.com. 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.

  • Letter
  • Published:

Experimental realization of a one-atom laser in the regime of strong coupling

Nature volume 425, pages 268–271 (2003)Cite this article

Abstract

Conventional lasers (from table-top systems to microscopic devices) typically operate in the so-called weak-coupling regime, involving large numbers of atoms and photons; individual quanta have a negligible impact on the system dynamics. However, this is no longer the case when the system approaches the regime of strong coupling for which the number of atoms and photons can become quite small. Indeed, the lasing properties of a single atom in a resonant cavity have been extensively investigated theoretically1,2,3,4,5,6,7,8,9,10,11. Here we report the experimental realization of a one-atom laser operated in the regime of strong coupling. We exploit recent advances12 in cavity quantum electrodynamics that allow one atom to be isolated in an optical cavity in a regime for which one photon is sufficient to saturate the atomic transition. The observed characteristics of the atom–cavity system are qualitatively different from those of the familiar many-atom case. Specifically, our measurements of the intracavity photon number versus pump intensity indicate that there is no threshold for lasing, and we infer that the output flux from the cavity mode exceeds that from atomic fluorescence by more than tenfold. Observations of the second-order intensity correlation function demonstrate that our one-atom laser generates manifestly quantum (nonclassical) light, typified by photon anti-bunching and sub-poissonian photon statistics.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: A simplified schematic of the experiment.
Figure 2: Total counting rate R recorded by detectors D1,2 is displayed as a function of time for two separate trapped atoms, with the counts summed over 5-ms bins.
Figure 3: The intracavity photon number n̄ ± σn, inferred from measurements as in Fig. 2, is plotted as a function of dimensionless pump intensity x ≡ (7/9) (I3/I4) for fixed I4 = 13 over two ranges of pump level x.
Figure 4: The intensity correlation function g(2)(τ) is given for two values of the pump intensity in a–d, where b and d show the central features of a and c over a smaller range of τ.

Similar content being viewed by others

References

  1. Mu, Y. & Savage, C. M. One-atom lasers. Phys. Rev. A 46, 5944–5954 (1992)

    Article  ADS  CAS  Google Scholar 

  2. Ginzel, C., Briegel, H.-J., Martini, U., Englert, B.-G. & Schenzle, A. Quantum optical master equations: The one-atom laser. Phys. Rev. A 48, 732–738 (1993)

    Article  ADS  CAS  Google Scholar 

  3. Pellizzari, T. & Ritsch, H. Preparation of stationary Fock states in a one-atom Raman laser. Phys. Rev. Lett. 72, 3973–3976 (1994)

    Article  ADS  CAS  Google Scholar 

  4. Pellizzari, T. & Ritsch, H. Photon statistics of the three-level one-atom laser. J. Mod. Opt. 41, 609–623 (1994)

    Article  ADS  CAS  Google Scholar 

  5. Horak, P., Gheri, K. M. & Ritsch, H. Quantum dynamics of a single-atom cascade laser. Phys. Rev. A. 51, 3257–3266 (1995)

    Article  ADS  CAS  Google Scholar 

  6. Meyer, G. M., Briegel, H.-J. & Walther, H. Ion-trap laser. Europhys. Lett. 37, 317–322 (1997)

    Article  ADS  CAS  Google Scholar 

  7. Löffler, M., Meyer, G. M. & Walther, H. Spectral properties of the one-atom laser. Phys. Rev. A 55, 3923–3930 (1997)

    Article  ADS  Google Scholar 

  8. Meyer, G. M., Löffler, M. & Walther, H. Spectrum of the ion-trap laser. Phys. Rev. A 56, R1099–R1102 (1997)

    Article  ADS  CAS  Google Scholar 

  9. Meyer, G. M. & Briegel, H.-J. Pump-operator treatment of the ion-trap laser. Phys. Rev. A 58, 3210–3220 (1998)

    Article  ADS  CAS  Google Scholar 

  10. Jones, B., Ghose, S., Clemens, J. P., Rice, P. R. & Pedrotti, L. M. Photon statistics of a single atom laser. Phys. Rev. A 60, 3267–3275 (1999)

    Article  ADS  CAS  Google Scholar 

  11. Kilin, S. Ya. & Karlovich, T. B. Single-atom laser: Coherent and nonclassical effects in the regime of a strong atom-field correlation. JETP 95, 805–819 (2002)

    Article  ADS  CAS  Google Scholar 

  12. McKeever, J. et al. State-insensitive cooling and trapping of single atoms in an optical cavity. Phys. Rev. Lett. 90, 133602 (2003)

    Article  ADS  CAS  Google Scholar 

  13. Sargent, M. III, Scully, M. O. & Lamb, W. E. Jr Laser Physics (Addison-Wesley, Reading, MA, 1974)

    Google Scholar 

  14. Haken, H. Laser Theory (Springer, Berlin, 1984)

    MATH  Google Scholar 

  15. Mandel, L. & Wolf, E. Optical Coherence and Quantum Optics (Cambridge Univ. Press, Cambridge, 1995)

    Book  Google Scholar 

  16. Carmichael, H. J. Statistical Methods in Quantum Optics 1 (Springer, Berlin, 1999)

    Book  Google Scholar 

  17. Gardiner, C. W. & Zoller, P. Quantum Noise (Springer, Berlin, 2000)

    Book  Google Scholar 

  18. Kimble, H. J. Strong interactions of single atoms and photons in cavity QED. Phys. Scr. T76, 127–137 (1998)

    Article  ADS  CAS  Google Scholar 

  19. Raithel, G., Wagner, C., Walther, H., Narducci, L. M. & Scully, M. O. Cavity Quantum Electrodynamics (ed. Berman, P.) 57–121 (Academic, San Diego, 1994)

    Google Scholar 

  20. Haroche, S. & Raimond, J. M. Cavity Quantum Electrodynamics (ed. Berman, P.) 123–170 (Academic, San Diego, 1994)

    Google Scholar 

  21. Meystre, P. in Progress in Optics Vol. XXX (ed. Wolf, E.) 261–355 (Elsevier, Amsterdam, 1992)

    Google Scholar 

  22. An, K. & Feld, M. S. Semiclassical four-level single-atom laser. Phys. Rev. A 56, 1662–1665 (1997)

    Article  ADS  CAS  Google Scholar 

  23. Chang, R. K. & Campillo, A. J. (eds) Optical Processes in Microcavities (World Scientific, Singapore, 1996)

  24. Vahala, K. J. Optical microcavities. Nature 424, 839–846 (2003)

    Article  ADS  CAS  Google Scholar 

  25. Ye, J., Vernooy, D. W. & Kimble, H. J. Trapping of single atoms in cavity QED. Phys. Rev. Lett. 83, 4987–4990 (1999)

    Article  ADS  CAS  Google Scholar 

  26. Rice, P. R. & Carmichael, H. J. Photon statistics of a cavity-QED laser: A comment on the laser-phase-transition analogy. Phys. Rev. A 50, 4318–4329 (1994)

    Article  ADS  CAS  Google Scholar 

  27. Boozer, A. D., Boca, A., Buck, J. R., McKeever, J. & Kimble, H. J. Comparison of theory and experiment for a one-atom laser in a regime of strong coupling. Phys. Rev. A (submitted); preprint available at 〈http://lanl.arxiv.org/archive/quant-ph〉

  28. Metcalf, H. J. & van der Straten, P. Laser Cooling and Trapping (Springer, New York, 1999)

    Book  Google Scholar 

  29. Boiron, D. et al. Laser cooling of cesium atoms in gray optical molasses down to 1.1 µK. Phys. Rev. A 53, R3734–R3737 (1996)

    Article  ADS  CAS  Google Scholar 

  30. Corwin, K. L., Kuppens, S. J. M., Cho, D. & Wieman, C. E. Spin-polarized atoms in a circularly polarized optical dipole trap. Phys. Rev. Lett. 83, 1311–1314 (1999)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We gratefully acknowledge interactions with K. Birnbaum, C.-W. Chou, A. C. Doherty, L.-M. Duan, T. Lynn, T. Northup, S. Polyakov and D. M. Stamper-Kurn. This work was supported by the National Science Foundation, by the Caltech MURI Center for Quantum Networks, and by the Office of Naval Research.

Author information

Authors and Affiliations

  1. Norman Bridge Laboratory of Physics 12-33, California Institute of Technology, Pasadena, California, 91125, USA

    J. McKeever, A. Boca, A. D. Boozer, J. R. Buck & H. J. Kimble

Authors
  1. J. McKeever
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. Boca
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. A. D. Boozer
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. J. R. Buck
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. H. J. Kimble
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to H. J. Kimble.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

McKeever, J., Boca, A., Boozer, A. et al. Experimental realization of a one-atom laser in the regime of strong coupling. Nature 425, 268–271 (2003). https://doi.org/10.1038/nature01974

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature01974

This article is cited by

Comments

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.

Search

Advanced search

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