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A steady-state superradiant laser with less than one intracavity photon

Nature volume 484, pages 78–81 (2012)Cite this article

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Abstract

The spectral purity of an oscillator is central to many applications, such as detecting gravity waves1, defining the second2,3, ground-state cooling and quantum manipulation of nanomechanical objects4, and quantum computation5. Recent proposals6,7,8,9 suggest that laser oscillators which use very narrow optical transitions in atoms can be orders of magnitude more spectrally pure than present lasers. Lasers of this high spectral purity are predicted to operate deep in the ‘bad-cavity’, or superradiant, regime, where the bare atomic linewidth is much less than the cavity linewidth. Here we demonstrate a Raman superradiant laser source in which spontaneous synchronization of more than one million rubidium-87 atomic dipoles is continuously sustained by less than 0.2 photons on average inside the optical cavity. By operating at low intracavity photon number, we demonstrate isolation of the collective atomic dipole from the environment by a factor of more than ten thousand, as characterized by cavity frequency pulling measurements. The emitted light has a frequency linewidth, measured relative to the Raman dressing laser, that is less than that of single-particle decoherence linewidths and more than ten thousand times less than the quantum linewidth limit typically applied to ‘good-cavity’ optical lasers10, for which the cavity linewidth is much less than the atomic linewidth. These results demonstrate several key predictions for future superradiant lasers, which could be used to improve the stability of passive atomic clocks3 and which may lead to new searches for physics beyond the standard model11,12.

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Figure 1: A steady-state superradiant laser.
Figure 2: Repumping-induced quenching.
Figure 3: Phase coherence maintained with no intracavity photons.
Figure 4: Beyond good-cavity, optical laser stability.

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References

  1. Cagnoli, G. et al. Very high Q measurements on a fused silica monolithic pendulum for use in enhanced gravity wave detectors. Phys. Rev. Lett. 85, 2442–2445 (2000)

    Article  ADS  CAS  Google Scholar 

  2. Ludlow, A. D. et al. Sr lattice clock at 1 × 10−16 fractional uncertainty by remote optical evaluation with a Ca clock. Science 319, 1805–1808 (2008)

    Article  ADS  CAS  Google Scholar 

  3. Jiang, Y. Y. et al. Making optical atomic clocks more stable with 10−16-level laser stabilization. Nature Photon. 5, 158–161 (2011)

    Article  ADS  CAS  Google Scholar 

  4. Teufel, J. D. et al. Sideband cooling of micromechanical motion to the quantum ground state. Nature 475, 359–363 (2011)

    Article  ADS  CAS  Google Scholar 

  5. Leibfried, D., Blatt, R., Monroe, C. & Wineland, D. Quantum dynamics of single trapped ions. Rev. Mod. Phys. 75, 281–324 (2003)

    Article  ADS  CAS  Google Scholar 

  6. Meiser, D., Ye, J., Carlson, D. R. & Holland, M. J. Prospects for a millihertz-linewidth laser. Phys. Rev. Lett. 102, 163601–163604 (2009)

    Article  ADS  CAS  Google Scholar 

  7. Chen, J. Active optical clock. Chin. Sci. Bull. 54, 348–352 (2009)

    CAS  Google Scholar 

  8. Meiser, D. & Holland, M. J. Steady-state superradiance with alkaline-earth-metal atoms. Phys. Rev. A 81, 033847–033850 (2010)

    Article  ADS  Google Scholar 

  9. Meiser, D. & Holland, M. J. Intensity fluctuations in steady-state superradiance. Phys. Rev. A 81, 063827–063833 (2010)

    Article  ADS  Google Scholar 

  10. Schawlow, A. L. & Townes, C. H. Infrared and optical masers. Phys. Rev. 112, 1940–1949 (1958)

    Article  ADS  CAS  Google Scholar 

  11. Blatt, S. et al. New limits on coupling of fundamental constants to gravity using 87Sr optical lattice clocks. Phys. Rev. Lett. 100, 140801–140804 (2008)

    Article  ADS  CAS  Google Scholar 

  12. Fortier, T. M. et al. Precision atomic spectroscopy for improved limits on variation of the fine structure constant and local position invariance. Phys. Rev. Lett. 98, 070801–070804 (2007)

    Article  ADS  CAS  Google Scholar 

  13. Hartnett, J. & Nand, N. Ultra-low vibration pulse-tube cryocooler stabilized cryogenic sapphire oscillator with 10−16 fractional frequency stability. IEEE Trans. Microw. Theory Tech. 58, 3580–3586 (2010)

    ADS  Google Scholar 

  14. Young, B. C., Cruz, F. C., Itano, W. M. & Bergquist, J. C. Visible lasers with subhertz linewidths. Phys. Rev. Lett. 82, 3799–3802 (1999)

    Article  ADS  CAS  Google Scholar 

  15. Kolobov, M. I., Davidovich, L., Giacobino, E. & Fabre, C. Role of pumping statistics and dynamics of atomic polarization in quantum fluctuations of laser sources. Phys. Rev. A 47, 1431–1446 (1993)

    Article  ADS  CAS  Google Scholar 

  16. Kuppens, S. J. M., van Exter, M. P. & Woerdman, J. P. Quantum-limited linewidth of a bad-cavity laser. Phys. Rev. Lett. 72, 3815–3818 (1994)

    Article  ADS  CAS  Google Scholar 

  17. Wang, H., Goorskey, D. J., Burkett, W. H. & Xiao, M. Cavity-linewidth narrowing by means of electromagnetically induced transparency. Opt. Lett. 25, 1732–1734 (2000)

    Article  ADS  CAS  Google Scholar 

  18. Dicke, R. H. Coherence in spontaneous radiation processes. Phys. Rev. 93, 99–110 (1954)

    Article  ADS  CAS  Google Scholar 

  19. Kleppner, D., Goldenberg, H. M. & Ramsey, N. F. Theory of the hydrogen maser. Phys. Rev. 126, 603–615 (1962)

    Article  ADS  Google Scholar 

  20. Benmessai, K. et al. Measurement of the fundamental thermal noise limit in a cryogenic sapphire frequency standard using bimodal maser oscillations. Phys. Rev. Lett. 100, 233901–233904 (2008)

    Article  ADS  Google Scholar 

  21. Kuppens, S., van Exter, M., Woerdman, J. & Kolobov, M. Observation of the effect of spectrally inhomogeneous gain on the quantum-limited laser linewidth. Opt. Commun. 126, 79–84 (1996)

    Article  ADS  CAS  Google Scholar 

  22. Björk, G., Heitmann, H. & Yamamoto, Y. Spontaneous-emission coupling factor and mode characteristics of planar dielectric microcavity lasers. Phys. Rev. A 47, 4451–4463 (1993)

    Article  ADS  Google Scholar 

  23. Vrijsen, G., Hosten, O., Lee, J., Bernon, S. & Kasevich, M. A. Raman lasing with a cold atom gain medium in a high-finesse optical cavity. Phys. Rev. Lett. 107, 063904–063907 (2011)

    Article  ADS  Google Scholar 

  24. Hilico, L., Fabre, C. & Giacobino, E. Operation of a cold-atom laser in a magneto-optical trap. Europhys. Lett. 18, 685–688 (1992)

    Article  ADS  CAS  Google Scholar 

  25. Guerin, W., Michaud, F. & Kaiser, R. Mechanisms for lasing with cold atoms as the gain medium. Phys. Rev. Lett. 101, 093002–093005 (2008)

    Article  ADS  Google Scholar 

  26. Chan, H. W., Black, A. T. & Vuletić, V. Observation of collective-emission-induced cooling of atoms in an optical cavity. Phys. Rev. Lett. 90, 063003–063006 (2003)

    Article  ADS  Google Scholar 

  27. Chen, Z., Bohnet, J. G., Sankar, S. R., Dai, J. & Thompson, J. K. Conditional spin squeezing of a large ensemble via the vacuum Rabi splitting. Phys. Rev. Lett. 106, 133601–133604 (2011)

    Article  ADS  Google Scholar 

  28. McKeever, J., Boca, A., Boozer, A. D., Buck, J. R. & Kimble, H. J. Experimental realization of a one-atom laser in the regime of strong coupling. Nature 425, 268–271 (2003)

    Article  ADS  CAS  Google Scholar 

  29. Leibrandt, D. R., Thorpe, M. J., Bergquist, J. C. & Rosenband, T. Field-test of a robust, portable, frequency-stable laser. Opt. Express 19, 10278–10286 (2011)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank J. Ye and A. M. Rey for discussions. J.G.B., Z.C., J.M.W. and J.K.T. acknowledge support from NSF PFC, NIST and ARO. M.J.H. and D.M. acknowledge support from the DARPA QuASaR programme through a grant from ARO and from NSF. J.G.B. acknowledges support from NSF GRF, and Z.C. acknowledges support from A*STAR Singapore.

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Author notes

  1. Dominic Meiser

    Present address: Present address: Tech-X Corporation, 5621 Arapahoe Avenue, Suite A, Boulder, Colorado 80303, USA.,

Authors and Affiliations

  1. Department of Physics, JILA, NIST and University of Colorado, University of Colorado, 440 UCB, Boulder, Colorado 80309, USA,

    Justin G. Bohnet, Zilong Chen, Joshua M. Weiner, Dominic Meiser, Murray J. Holland & James K. Thompson

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  1. Justin G. Bohnet
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  4. Dominic Meiser
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Contributions

J.G.B., Z.C., J.M.W. and J.K.T. designed and built the experiment. J.G.B. and Z.C. performed the measurements. J.G.B., Z.C., J.M.W. and J.K.T. analysed the results. D.M., M.J.H. and J.K.T. provided the theoretical analysis. J.G.B. and J.K.T. wrote the manuscript. All authors discussed the results and text of the manuscript.

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Correspondence to James K. Thompson.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Text that expands on details in the original paper, comprising: Experimental Details; Primary Experimental Configuration; Secondary Experimental Configuration; Atom Loss; Photon Number and Phase Uncertainty; Phasor Correlation; and Lorentzian Fits. The file also includes Supplementary Figures 1-2, which are detailed diagrams of the physical experimental setup and atomic energy levels. (PDF 489 kb)

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Bohnet, J., Chen, Z., Weiner, J. et al. A steady-state superradiant laser with less than one intracavity photon. Nature 484, 78–81 (2012). https://doi.org/10.1038/nature10920

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