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Generation of ultrastable microwaves via optical frequency division

Abstract

There has been increased interest in the use and manipulation of optical fields to address the challenging problems that have traditionally been approached with microwave electronics. Some examples that benefit from the low transmission loss, agile modulation and large bandwidths accessible with coherent optical systems include signal distribution, arbitrary waveform generation and novel imaging1. We extend these advantages to demonstrate a microwave generator based on a high-quality-factor (Q) optical resonator and a frequency comb functioning as an optical-to-microwave divider. This provides a 10 GHz electrical signal with fractional frequency instability of ≤8 × 10−16 at 1 s, a value comparable to that produced by the best microwave oscillators, but without the need for cryogenic temperatures. Such a low-noise source can benefit radar systems2 and improve the bandwidth and resolution of communications and digital sampling systems3, and can also be valuable for large baseline interferometry4, precision spectroscopy and the realization of atomic time5,6,7.

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Figure 1: How the OFC from a mode-locked laser acts as an optical frequency divider and comparator.
Figure 2: Schematic of the experimental set-up used for generation and characterization of the 10 GHz low-noise microwaves.
Figure 3: Phase-noise spectrum of the photonically generated 10 GHz microwaves and contributing noise sources.
Figure 4: Time record and fractional frequency instability.
Figure 5: Approximate single-sideband phase noise for several leading microwave generation technologies in the 10 GHz range.

References

  1. 1

    Capmany, J. & Novak, D. Microwave photonics combines two worlds. Nature Photon. 1, 319–330 (2007).

    ADS  Article  Google Scholar 

  2. 2

    Scheer, J. A. & Kurtz, J. Coherent Radar Performance Estimation (Artech House, 1993).

    Google Scholar 

  3. 3

    Valley, G. C. Photonic analog-to-digital converters. Opt. Express 15, 1955–1982 (2007).

    ADS  Article  Google Scholar 

  4. 4

    Doeleman, S. in Frequency standards and metrology: Proceedings of the 7th symposium (ed Maleki, L.) 175–183 (World Scientific, 2009).

    Book  Google Scholar 

  5. 5

    Santarelli, G. et al. Quantum projection noise in an atomic fountain: a high stability cesium frequency standard. Phys. Rev. Lett. 82, 4619–4622 (1999).

    ADS  Article  Google Scholar 

  6. 6

    Weyers, S., Lipphardt, B. & Schnatz, H. Reaching the quantum limit in a fountain clock using a microwave oscillator phase locked to an ultrastable laser. Phys. Rev. A 79, 031803 (2009).

    ADS  Article  Google Scholar 

  7. 7

    Millo, J. et al. Ultralow noise microwave generation with fiber-based optical frequency comb and application to atomic fountain clock. Appl. Phys. Lett. 94, 141105 (2009).

    ADS  Article  Google Scholar 

  8. 8

    Eliyahu, D., Seidel, D. & Maleki, L. in Proceedings of the IEEE International Frequency Control Symposium, 811–814 (2008).

  9. 9

    Savchenkov, A. A., Rubiola, E., Matsko, A. B., Ilchenko, V. S. & Maleki, L. Phase noise of whispering gallery photonic hyper-parametric microwave oscillators. Opt. Express 16, 4130–4144 (2008).

    ADS  Article  Google Scholar 

  10. 10

    Callahan, P. T., Gross, M. C. & Dennis, M. L. in 2010 IEEE Topical Meeting on Microwave Photonics (MWP), 155–158 (2010).

  11. 11

    Bartels, A. et al. Femtosecond laser based synthesis of ultrastable microwave signals from optical frequency references. Opt. Lett. 30, 667–669 (2005).

    ADS  Article  Google Scholar 

  12. 12

    McFerran, J. J. et al. Low noise synthesis of microwave signals from an optical source. Electron. Lett. 41, 36–37 (2005).

    Article  Google Scholar 

  13. 13

    Zhang, W. et al. Sub-100 attoseconds stability optics-to-microwave synchronization. Appl. Phys. Lett. 96, 211105 (2010).

    ADS  Article  Google Scholar 

  14. 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).

    ADS  Article  Google Scholar 

  15. 15

    Webster, S. A., Oxborrow, M. & Gill, P. Subhertz-linewidth Nd:YAG laser. Opt. Lett. 29, 1497–1499 (2004).

    ADS  Article  Google Scholar 

  16. 16

    Millo, J. et al. Ultrastable lasers based on vibration insensitive cavities. Phys. Rev. A 79, 053829 (2009).

    ADS  Article  Google Scholar 

  17. 17

    Ludlow, A. D. et al. Compact, thermal-noise-limited optical cavity for diode laser stabilization at 1×10−15. Opt. Lett. 32, 641–643 (2007).

    ADS  Article  Google Scholar 

  18. 18

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

    ADS  Article  Google Scholar 

  19. 19

    Thorpe, M. J., Fortier, T. M., Kirchner, M. S., Rosenband, T. & Rippe, L. Frequency-stabilization to 6×10−16 via spectral hole burning. (submitted to Nature Photonics).

  20. 20

    Mann, A. G., Sheng, C. & Luiten, A. N. Cryogenic sapphire oscillator with exceptionally high frequency stability. IEEE Trans. Instrum. Meas. 50, 519–521 (2001).

    Article  Google Scholar 

  21. 21

    Locke, C. R., Ivanov, E. N., Hartnett, J. G., Stanwix, P. L. & Tobar, M. E. Invited article: Design techniques and noise properties of ultrastable cryogenically cooled sapphire-dielectric resonator oscillators. Rev. Sci. Instrum. 79, 051301 (2008).

    ADS  Article  Google Scholar 

  22. 22

    Grop, S. et al. ELISA: a cryocooled 10 GHz oscillator with 10−15 frequency stability. Rev. Sci. Instrum. 81, 025102 (2010).

    ADS  Article  Google Scholar 

  23. 23

    Grop, S. et al. 10 GHz cryocooled sapphire oscillator with extremely low phase noise. Electron. Lett. 46, 420–422 (2010).

    Article  Google Scholar 

  24. 24

    Diddams, S. A. et al. Improved signal-to-noise ratio of 10 GHz microwave signals generated with a mode-filtered femtosecond laser frequency comb. Opt. Express 17, 3331–3340 (2009).

    ADS  Article  Google Scholar 

  25. 25

    Ivanov, E. N. & Tobar, M. E. Low phase-noise sapphire crystal microwave oscillators: current status. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 56, 263–269 (2009).

    Article  Google Scholar 

  26. 26

    Ma, L-S., Jungner, P., Ye, J. & Hall, J. L. Delivering the same optical frequency at two places: accurate cancellation of phase noise introduced by an optical fiber or other time-varying path. Opt. Lett. 19, 1777–1779 (1994).

    ADS  Article  Google Scholar 

  27. 27

    Fortier, T. M., Bartels, A. & Diddams, S. A. Octave-spanning Ti:sapphire laser with a repetition rate of 1 GHz for optical frequency measurements and comparisons. Opt. Lett. 31, 1011–1013 (2006).

    ADS  Article  Google Scholar 

  28. 28

    Taylor, J. et al. Characterization of power-to-phase conversion in high-speed P-I-N photodiodes. IEEE Photon. J. 3, 140–151 (2010).

    ADS  Article  Google Scholar 

  29. 29

    Dawkins, S. T., McFerran, J. J. & Luiten, A. N. Considerations on the measurement of the stability of oscillators with frequency counters. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 54, 918–925 (2007).

    Article  Google Scholar 

Download references

Acknowledgements

The authors thank A. Hati, L. Hollberg, D. Howe, C. Nelson, N. Newbury and S. Papp for their contributions and comments on this manuscript, and A. Joshi and S. Datta of Discovery Semiconductor for providing the 10 GHz InGaAs photodiodes. This work was supported by NIST. It is a contribution of an agency of the US Government and is not subject to copyright in the USA. Mention of specific products or trade names does not constitute an endorsement by NIST.

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T.M.F., M.S.K., F.Q., J.T. and S.A.D. built, characterized and operated the femtosecond lasers and measurement systems. J.C.B., T.R., N.L., A.L., Y.J. and C.W.O. constructed and operated the stable c.w. laser sources. S.A.D., T.M.F. and F.Q. acquired and analysed the data and prepared the manuscript.

Corresponding authors

Correspondence to T. M. Fortier or S. A. Diddams.

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The authors declare no competing financial interests.

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Fortier, T., Kirchner, M., Quinlan, F. et al. Generation of ultrastable microwaves via optical frequency division. Nature Photon 5, 425–429 (2011). https://doi.org/10.1038/nphoton.2011.121

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