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A frequency comb in the extreme ultraviolet

Abstract

Since 1998, the interaction of precision spectroscopy and ultrafast laser science has led to several notable accomplishments. Femtosecond laser optical frequency ‘combs’ (evenly spaced spectral lines) have revolutionized the measurement of optical frequencies1,2 and enabled optical atomic clocks3. The same comb techniques have been used to control the waveform of ultrafast laser pulses, which permitted the generation of single attosecond pulses4, and have been used in a recently demonstrated ‘oscilloscope’ for light waves5. Here we demonstrate intra-cavity high harmonic generation in the extreme ultraviolet, which promises to lead to another joint frontier of precision spectroscopy and ultrafast science. We have generated coherent extreme ultraviolet radiation at a repetition frequency of more than 100 MHz, a 1,000-fold improvement over previous experiments6. At such a repetition rate, the mode spacing of the frequency comb, which is expected to survive the high harmonic generation process, is large enough for high resolution spectroscopy. Additionally, there may be many other applications of such a quasi-continuous compact and coherent extreme ultraviolet source, including extreme ultraviolet holography, microscopy, nanolithography and X-ray atomic clocks.

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Figure 1: The XUV laser set-up.
Figure 2: Normalized spectrum of the pump laser (black) and the circulating pulse in the enhancement resonator (red) when locked.
Figure 3: Harmonic spectrum obtained with the resonator locked and the xenon jet on.
Figure 4: Frequency comb coherence.
Figure 5: Generated power versus the fundamental intensity I for three spectral features.

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References

  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. Femtosecond optical frequency combs. Rev. Mod. Phys. 75, 325–342 (2003)

    Article  ADS  CAS  Google Scholar 

  3. Diddams, S. A. et al. An optical clock based on a single trapped 199Hg+ ion. Science 293, 825–828 (2001)

    Article  ADS  CAS  Google Scholar 

  4. Baltuška, A. et al. Attosecond control of electronic processes by intense light fields. Nature 421, 611–615 (2003)

    Article  ADS  Google Scholar 

  5. Goulielmakis, E. et al. Direct measurement of light waves. Science 305, 1267–1269 (2004)

    Article  ADS  CAS  Google Scholar 

  6. Lindner, F. et al. High-order harmonic generation at a repetition rate of 100 kHz. Phys. Rev. A 68, 013814 (2003)

    Article  ADS  Google Scholar 

  7. Rafac, R. J. et al. Sub-dekahertz ultraviolet spectroscopy of 199Hg+. Phys. Rev. Lett. 85, 2462–2465 (2000)

    Article  ADS  CAS  Google Scholar 

  8. Strickland, D. & Mourou, G. Compression of amplified chirped optical pulses. Opt. Commun. 56, 219–221 (1985)

    Article  ADS  Google Scholar 

  9. Seres, J. et al. Laser technology: Source of coherent kiloelectronvolt X-rays. Nature 433, 596 (2005)

    Article  ADS  CAS  Google Scholar 

  10. Schoof, A., Grünert, J., Ritter, S. & Hemmerich, A. Reducing the linewidth of a diode laser below 30 Hz by stabilization to a reference cavity with a finesse above 105. Opt. Lett. 26, 1562–1564 (2001)

    Article  ADS  CAS  Google Scholar 

  11. Polzik, E. S. & Kimble, H. J. Frequency doubling with KNbO3 in an external cavity. Opt. Lett. 16, 1400–1402 (1991)

    Article  ADS  CAS  Google Scholar 

  12. Reichert, J., Holzwarth, R., Udem, T. & Hänsch, T. W. Measuring the frequency of light with mode-locked lasers. Opt. Commun. 172, 59–68 (1999)

    Article  ADS  CAS  Google Scholar 

  13. Jones, R. J. & Ye, J. Femtosecond pulse amplification by coherent addition in a passive optical cavity. Opt. Lett. 27, 1848–1850 (2002)

    Article  ADS  Google Scholar 

  14. Petersen, J. C. & Luiten, A. N. Short pulses in optical resonators. Opt. Express 11, 2975–2981 (2003)

    Article  ADS  CAS  Google Scholar 

  15. Yanovsky, V. P. & Wise, F. W. Frequency doubling of 100-fs pulses with 50% efficiency by use of a resonant enhancement cavity. Opt. Lett. 19, 1952–1954 (1994)

    Article  ADS  CAS  Google Scholar 

  16. Jones, R. J. & Ye, J. High-repetition-rate coherent femtosecond pulse amplification with an external passive optical cavity. Opt. Lett. 29, 2812–2814 (2004)

    Article  ADS  Google Scholar 

  17. Baklanov, Y. V. & Chebotayev, V. P. Narrow resonances of 2-photon absorption of super-narrow pulses in a gas. Appl. Phys. 12, 97–99 (1977)

    Article  ADS  CAS  Google Scholar 

  18. Snadden, M. J., Bell, A. S., Riis, E. & Ferguson, A. I. Two-photon spectroscopy of laser-cooled Rb using a mode-locked laser. Opt. Commun. 125, 70–76 (1996)

    Article  ADS  CAS  Google Scholar 

  19. Eckstein, J. N., Ferguson, A. I. & Hänsch, T. W. High-resolution spectroscopy with ultrashort light-pulses. J. Opt. Soc. Am. 68, 646 (1978)

    ADS  Google Scholar 

  20. Marian, A., Stowe, M. C., Lawall, J. R., Felinto, D. & Ye, J. United time-frequency spectroscopy for dynamics and global structure. Science 306, 2063–2068 (2004)

    Article  ADS  CAS  Google Scholar 

  21. Witte, S., Zinkstok, R. T., Ubachs, W., Hogervorst, W. & Eikema, K. S. E. Deep-ultraviolet quantum interference metrology with ultrashort laser pulses. Science 307, 400–403 (2005)

    Article  ADS  CAS  Google Scholar 

  22. Bellini, M. et al. Temporal coherence of ultrashort high-order harmonic pulses. Phys. Rev. Lett. 81, 297–300 (1998)

    Article  ADS  CAS  Google Scholar 

  23. López-Martens, R. et al. Amplitude and phase control of attosecond light pulses. Phys. Rev. Lett. 94, 033001 (2005)

    Article  ADS  Google Scholar 

  24. Jones, R. J., Moll, K., Thorpe, M., 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 

  25. Wahlström, C. G. et al. High-order harmonic-generation in rare-gases with an intense short-pulse laser. Phys. Rev. A 48, 4709–4720 (1993)

    Article  ADS  Google Scholar 

  26. Constant, E. et al. Optimizing high harmonic generation in absorbing gases: Model and experiment. Phys. Rev. Lett. 82, 1668–1671 (1999)

    Article  ADS  CAS  Google Scholar 

  27. Thorpe, M. J., Jason, J. R., Moll, K., Ye, J. & Lalezari, R. Precise measurements of optical cavity dispersion and mirror coating properties via femtosecond combs. Opt. Expr. 13, 882–888 (2005)

    Article  ADS  Google Scholar 

  28. Fernandez, A. et al. Chirped-pulse oscillators: a route to high-power femtosecond pulses without external amplification. Opt. Lett. 29, 1366–1368 (2004)

    Article  ADS  CAS  Google Scholar 

  29. Fischer, M. et al. New limits on the drift of fundamental constants from laboratory measurements. Phys. Rev. Lett. 92, 230802 (2004)

    Article  ADS  CAS  Google Scholar 

  30. Hänsch, T. W. & Couillaud, B. Laser frequency stabilization by polarization spectroscopy of a reflecting reference cavity. Opt. Commun. 35, 441–444 (1980)

    Article  ADS  Google Scholar 

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Acknowledgements

We thank A. Apolonski and M. Yu. Ivanov for discussions, and E. Seres and J. Seres for lending us the XUV monochromator.

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Correspondence to Christoph Gohle.

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Gohle, C., Udem, T., Herrmann, M. et al. A frequency comb in the extreme ultraviolet. Nature 436, 234–237 (2005). https://doi.org/10.1038/nature03851

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