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Optical frequency comb generation from a monolithic microresonator


Optical frequency combs1,2,3 provide equidistant frequency markers in the infrared, visible and ultraviolet4,5, and can be used to link an unknown optical frequency to a radio or microwave frequency reference6,7. Since their inception, frequency combs have triggered substantial advances in optical frequency metrology and precision measurements6,7 and in applications such as broadband laser-based gas sensing8 and molecular fingerprinting9. Early work generated frequency combs by intra-cavity phase modulation10,11; subsequently, frequency combs have been generated using the comb-like mode structure of mode-locked lasers, whose repetition rate and carrier envelope phase can be stabilized12. Here we report a substantially different approach to comb generation, in which equally spaced frequency markers are produced by the interaction between a continuous-wave pump laser of a known frequency with the modes of a monolithic ultra-high-Q microresonator13 via the Kerr nonlinearity14,15. The intrinsically broadband nature of parametric gain makes it possible to generate discrete comb modes over a 500-nm-wide span (70 THz) around 1,550 nm without relying on any external spectral broadening. Optical-heterodyne-based measurements reveal that cascaded parametric interactions give rise to an optical frequency comb, overcoming passive cavity dispersion. The uniformity of the mode spacing has been verified to within a relative experimental precision of 7.3 × 10-18. In contrast to femtosecond mode-locked lasers16, this work represents a step towards a monolithic optical frequency comb generator, allowing considerable reduction in size, complexity and power consumption. Moreover, the approach can operate at previously unattainable repetition rates17, exceeding 100 GHz, which are useful in applications where access to individual comb modes is required, such as optical waveform synthesis18, high capacity telecommunications or astrophysical spectrometer calibration19.

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Figure 1: Broadband parametric frequency conversion from a monolithic toroidal microresonator.
Figure 2: Multi-heterodyne beat note detection.
Figure 3: Probing the equidistance of the comb structure.
Figure 4: Verification of the equidistant mode spacing.


  1. Udem, T., Holzwarth, R. & Hänsch, T. W. Optical frequency metrology. Nature 416, 233–237 (2002)

    Article  ADS  CAS  Google Scholar 

  2. Cundiff, S. T. & Ye, J. Colloquium: Femtosecond optical frequency combs. Rev. Mod. Phys. 75, 325–342 (2003)

    Article  ADS  CAS  Google Scholar 

  3. Ye, J. & Cundiff, S. T. Femtosecond Optical Frequency Comb: Principle, Operation and Applications (Springer, New York, 2005)

    Book  Google Scholar 

  4. Jones, R. J., Moll, K. D., Thorpe, M. J. & Ye, J. Phase-coherent frequency combs in the vacuum ultraviolet via high-harmonic generation inside a femtosecond enhancement cavity. Phys. Rev. Lett. 94, 193201 (2005)

    Article  ADS  Google Scholar 

  5. Gohle, C. et al. A frequency comb in the extreme ultraviolet. Nature 436, 234–237 (2005)

    Article  ADS  CAS  Google Scholar 

  6. Diddams, S. A. et al. Direct link between microwave and optical frequencies with a 300 THz femtosecond laser comb. Phys. Rev. Lett. 84, 5102–5105 (2000)

    Article  ADS  CAS  Google Scholar 

  7. Reichert, J. et al. Phase coherent vacuum-ultraviolet to radio frequency comparison with a mode-locked laser. Phys. Rev. Lett. 84, 3232–3235 (2000)

    Article  ADS  CAS  Google Scholar 

  8. Thorpe, M. J., Moll, K. D., Jones, J. J., Safdi, B. & Ye, J. Broadband cavity ringdown spectroscopy for sensitive and rapid molecular detection. Science 311, 1595–1599 (2006)

    Article  ADS  CAS  Google Scholar 

  9. Diddams, S. A., Hollberg, L. & Mbele, V. Molecular fingerprinting with the resolved modes of a femtosecond laser frequency comb. Nature 445, 627–630 (2007)

    Article  CAS  Google Scholar 

  10. Kourogi, M., Nakagawa, K. & Ohtsu, M. Wide-span optical frequency comb generator for accurate optical frequency difference measurement. IEEE J. Quantum Electron. 29, 2693–2701 (1993)

    Article  ADS  CAS  Google Scholar 

  11. Ye, J., Ma, L. S., Daly, T. & Hall, J. L. Highly selective terahertz optical frequency comb generator. Opt. Lett. 22, 301–303 (1997)

    Article  ADS  CAS  Google Scholar 

  12. Jones, D. J. et al. Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis. Science 288, 635–639 (2000)

    Article  ADS  CAS  Google Scholar 

  13. Armani, D. K., Kippenberg, T. J., Spillane, S. M. & Vahala, K. J. Ultra-high-Q toroid microcavity on a chip. Nature 421, 925–928 (2003)

    Article  ADS  CAS  Google Scholar 

  14. Kippenberg, T. J., Spillane, S. M. & Vahala, K. J. Kerr-nonlinearity optical parametric oscillation in an ultrahigh-Q toroid microcavity. Phys. Rev. Lett. 93, 083904 (2004)

    Article  ADS  CAS  Google Scholar 

  15. Savchenkov, A. A. et al. Low threshold optical oscillations in a whispering gallery mode CaF2 resonator. Phys. Rev. Lett. 93, 243905 (2004)

    Article  ADS  Google Scholar 

  16. Steinmeyer, G., Sutter, D. H., Gallmann, L., Matuschek, N. & Keller, U. Frontiers in ultrashort pulse generation: Pushing the limits in linear and nonlinear optics. Science 286, 1507–1512 (1999)

    Article  CAS  Google Scholar 

  17. Keller, U. Recent developments in compact ultrafast lasers. Nature 424, 831–838 (2003)

    Article  ADS  CAS  Google Scholar 

  18. Weiner, A. M. Femtosecond pulse shaping using spatial light modulators. Rev. Sci. Instrum. 71, 1929–1960 (2000)

    Article  ADS  CAS  Google Scholar 

  19. Murphy, M. T. et al. High-precision wavelength calibration with laser frequency combs. Mon. Not. R. Astron. Soc. 380, 839–847 (2007)

    Article  ADS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

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

    Book  Google Scholar 

  22. Spillane, S. M., Kippenberg, T. J. & Vahala, K. J. Ultralow-threshold Raman laser using a spherical dielectric microcavity. Nature 415, 621–623 (2002)

    Article  ADS  CAS  Google Scholar 

  23. Carmon, T. & Vahala, K. J. Visible continuous emission from a silica microphotonic device by the third harmonic generation. Nature Phys. 3, 430–435 (2007)

    Article  ADS  CAS  Google Scholar 

  24. Dunn, M. H. & Ebrahimzadeh, M. Parametric generation of tunable light from continuous-wave to femtosecond pulses. Science 286, 1513–1517 (1999)

    Article  CAS  Google Scholar 

  25. Foster, M. A. et al. Broad-band optical parametric gain on a silicon photonic chip. Nature 441, 960–963 (2006)

    Article  ADS  CAS  Google Scholar 

  26. Stolen, R. H. & Bjorkholm, J. E. Parametric amplification and frequency-conversion in optical fibers. IEEE J. Quantum Electron. 18, 1062–1072 (1982)

    Article  ADS  Google Scholar 

  27. Spillane, S. M., Kippenberg, T. J., Painter, O. J. & Vahala, K. J. Ideality in a fiber-taper-coupled microresonator system for application to cavity quantum electrodynamics. Phys. Rev. Lett. 91, 043902 (2003)

    Article  ADS  CAS  Google Scholar 

  28. Kubina, P. et al. Long term comparison of two fiber based frequency comb systems. Opt. Expr. 13, 904–909 (2005)

    Article  ADS  Google Scholar 

  29. Schliesser, A., Brehm, M., Keilmann, F. & van der Weide, D. W. Frequency-comb infrared spectrometer for rapid, remote chemical sensing. Opt. Expr. 13, 9029–9038 (2005)

    Article  ADS  CAS  Google Scholar 

  30. Agha, I. H., Okawachi, Y., Foster, M. A., Sharping, J. E. & Gaeta, A. L. Four-wave mixing parametric oscillations in dispersion-compensated high-Q silica microspheres. Phys. Rev. A 76, 043837 (2007)

    Article  ADS  Google Scholar 

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We thank T. W. Hänsch, T. Udem, K. J. Vahala and S. A. Diddams for critical discussions and suggestions. T.J.K. acknowledges support via an Independent Max Planck Junior Research Group. This work was funded as part of a Marie Curie Excellence Grant (RG-UHQ), the DFG funded Nanosystems Initiative Munich (NIM) and a Marie Curie Reintegration Grant (JRG-UHQ). We thank J. Kotthaus for access to clean-room facilities for sample fabrication.

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Correspondence to T. J. Kippenberg.

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The file contains Supplementary Notes, Supplementary Figures S1-S6 with Legends and Supplementary Table S1 (PDF 1298 kb)

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Del’Haye, P., Schliesser, A., Arcizet, O. et al. Optical frequency comb generation from a monolithic microresonator. Nature 450, 1214–1217 (2007).

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