OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 20 — Sep. 24, 2012
  • pp: 22034–22041

Direct comparison of a Ca+ single-ion clock against a Sr lattice clock to verify the absolute frequency measurement

Kensuke Matsubara, Hidekazu Hachisu, Ying Li, Shigeo Nagano, Clayton Locke, Asahiko Nogami, Masatoshi Kajita, Kazuhiro Hayasaka, Tetsuya Ido, and Mizuhiko Hosokawa  »View Author Affiliations

Optics Express, Vol. 20, Issue 20, pp. 22034-22041 (2012)

View Full Text Article

Enhanced HTML    Acrobat PDF (833 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



Optical frequency comparison of the 40Ca+ clock transition νCa (2S1/2-2D5/2, 729nm) against the 87Sr optical lattice clock transition νSr (1S0-3P0, 698nm) has resulted in a frequency ratio νCa / νSr = 0.957 631 202 358 049 9(2 3). The rapid nature of optical comparison allowed the statistical uncertainty of frequency ratio νCa / νSr to reach 1 × 10−15 in 1000s and yielded a value consistent with that calculated from separate absolute frequency measurements of νCa using the International Atomic Time (TAI) link. The total uncertainty of the frequency ratio using optical comparison (free from microwave link uncertainties) is smaller than that obtained using absolute frequency measurement, demonstrating the advantage of optical frequency evaluation. We note that the absolute frequency of 40Ca+ we measure deviates from other published values by more than three times our measurement uncertainty.

© 2012 OSA

OCIS Codes
(020.0020) Atomic and molecular physics : Atomic and molecular physics
(120.3940) Instrumentation, measurement, and metrology : Metrology

ToC Category:
Instrumentation, Measurement, and Metrology

Original Manuscript: July 4, 2012
Revised Manuscript: September 3, 2012
Manuscript Accepted: September 4, 2012
Published: September 11, 2012

Kensuke Matsubara, Hidekazu Hachisu, Ying Li, Shigeo Nagano, Clayton Locke, Asahiko Nogami, Masatoshi Kajita, Kazuhiro Hayasaka, Tetsuya Ido, and Mizuhiko Hosokawa, "Direct comparison of a Ca+ single-ion clock against a Sr lattice clock to verify the absolute frequency measurement," Opt. Express 20, 22034-22041 (2012)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. K. Matsubara, K. Hayasaka, Y. Li, H. Ito, S. Nagano, M. Kajita, and M. Hosokawa, “Frequency measurement of the optical clock transition of 40Ca+ ions with an uncertainty of 10−14 level,” Appl. Phys. Express 1, 067011 (2008). [CrossRef]
  2. J. Guéna, M. Abgrall, D. Rovera, P. Laurent, B. Chupin, M. Lours, G. Santarelli, P. Rosenbusch, M. E. Tobar, R. Li, K. Gibble, A. Clairon, and S. Bize, “Progress in atomic fountains at LNE-SYRTE,” IEEE Trans. Ultrason., Ferroelectr., Freq. Cont. 59, 391–420 (2012).
  3. C. W. Chou, D. B. Hume, J. C. J. Koelemeij, D. J. Wineland, and T. Rosenband, “Frequency comparison of two high-accuracy Al+ optical clocks,” Phys. Rev. Lett. 104(7), 070802 (2010). [CrossRef] [PubMed]
  4. P. A. Williams, W. C. Swann, and N. R. Newbury, “High-stability transfer of an optical frequency over long fiber-optic links,” J. Opt. Soc. Am. B 25(8), 1284–1293 (2008). [CrossRef]
  5. K. Predehl, G. Grosche, S. M. F. Raupach, S. Droste, O. Terra, J. Alnis, Th. Legero, T. W. Hänsch, Th. Udem, R. Holzwarth, and H. Schnatz, “A 920-kilometer optical fiber link for frequency metrology at the 19th decimal place,” Science 336(6080), 441–444 (2012). [CrossRef] [PubMed]
  6. A. Yamaguchi, M. Fujieda, M. Kumagai, H. Hachisu, S. Nagano, Y. Li, T. Ido, T. Takano, M. Takamoto, and H. Katori, “Direct comparison of distant optical lattice clocks at the 10−16 uncertainty,” Appl. Phys. Express 4(8), 082203 (2011). [CrossRef]
  7. M. Fujieda, M. Kumagai, S. Nagano, A. Yamaguchi, H. Hachisu, and T. Ido, “All-optical link for direct comparison of distant optical clocks,” Opt. Express 19(17), 16498–16507 (2011). [CrossRef] [PubMed]
  8. T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; Metrology at the 17th decimal place,” Science 319(5871), 1808–1812 (2008). [CrossRef] [PubMed]
  9. M. Takamoto, F.-L. Hong, R. Higashi, and H. Katori, “An optical lattice clock,” Nature 435(7040), 321–324 (2005). [CrossRef] [PubMed]
  10. G. K. Campbell, A. D. Ludlow, S. Blatt, J. W. Thomsen, M. J. Martin, M. H. G. de Miranda, T. Zelevinsky, M. M. Boyd, J. Ye, S. A. Diddams, T. P. Heavner, T. E. Parker, and S. R. Jefferts, “The absolute frequency of the 87Sr optical clock transition,” Metrologia 45(5), 539–548 (2008). [CrossRef]
  11. X. Baillard, M. Fouche, R. Le Targat, P. G. Westergaard, A. Lecallier, F. Chapelet, M. Abgrall, G. D. Rovera, P. Laurent, P. Rosenbusch, S. Bize, G. Santarelli, A. Clairon, P. Lemonde, G. Grosche, B. Lipphardt, and H. Schnatz, “An optical lattice clock with spin-polarized 87Sr atoms,” Eur. Phys. J. D 48(1), 11–17 (2008). [CrossRef]
  12. St. Falke, H. Schnatz, J. S. R. V. Winfred, T. Middelmann, S. Vogt, S. Weyers, B. Lipphardt, G. Grosche, F. Riehle, U. Sterr, and C. Lisdat, “The 87Sr optical frequency standard at PTB,” Metrologia 48(5), 399–407 (2011). [CrossRef]
  13. A. Yamaguchi, N. Shiga, S. Nagano, Y. Li, H. Ishijima, H. Hachisu, M. Kumagai, and T. Ido, “Stability transfer between two clock lasers operating at different wavelengths for absolute frequency measurement of clock transition in 87Sr,” Appl. Phys. Express 5(2), 022701 (2012). [CrossRef]
  14. M. Chwalla, J. Benhelm, K. Kim, G. Kirchmair, T. Monz, M. Riebe, P. Schindler, A. S. Villar, W. Hänsel, C. F. Roos, R. Blatt, M. Abgrall, G. Santarelli, G. D. Rovera, and Ph. Laurent, “Absolute frequency measurement of the 40Ca+ 4s2S1/2-3d2D5/2 clock transition,” Phys. Rev. Lett. 102(2), 023002 (2009). [CrossRef] [PubMed]
  15. Y. Huang, J. Cao, P. Liu, K. Liang, B. Ou, H. Guan, X. Huang, T. Li, and K. Gao, “Hertz-level measurement of the 40Ca+ 4s2S1/2–3d2D5/2 clock transition frequency with respect to the SI second through the Global Positioning System,” Phys. Rev. A 85(3), 030503 (2012). [CrossRef]
  16. Y. Li, S. Nagano, K. Matsubara, H. Ito, M. Kajita, and M. Hosokawa, “Narrow-line and frequency tunable diode laser system for S–D transition of Ca+ ions,” Jpn. J. Appl. Phys. 47(8), 6327–6332 (2008). [CrossRef]
  17. L.-S. Ma, P. Jungner, J. Ye, and J. L. Hall, “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(21), 1777–1779 (1994). [CrossRef] [PubMed]
  18. B. Arora, M. S. Safronova, and C. W. Clark, “Blackbody-radiation shift in a 43Ca+ ion optical frequency standard,” Phys. Rev. A 76(6), 064501 (2007). [CrossRef]
  19. G. P. Barwood, H. S. Margolis, G. Huang, P. Gill, and H. A. Klein, “Measurement of the electric quadrupole moment of the 4d2D5/2 level in 88Sr+.,” Phys. Rev. Lett. 93(13), 133001 (2004). [CrossRef] [PubMed]
  20. H. S. Margolis, G. P. Barwood, G. Huang, H. A. Klein, S. N. Lea, K. Szymaniec, and P. Gill, “Hertz-level measurement of the optical clock frequency in a single 88Sr+ ion,” Science 306(5700), 1355–1358 (2004). [CrossRef] [PubMed]
  21. C. Degenhardt, T. Nazarova, C. Lisdat, H. Stoehr, U. Sterr, and F. Riehle, “Influence of chirped excitation pulses in an optical clock with ultracold calcium atoms,” IEEE Trans. Instrum. Meas. 54(2), 771–775 (2005). [CrossRef]
  22. S. Nagano, H. Ito, Y. Li, K. Matsubara, and M. Hosokawa, “Stable operation of femtosecond laser frequency combs with uncertainty at the 10−17 level toward optical frequency standards,” Jpn. J. Appl. Phys. 48(4), 042301 (2009). [CrossRef]
  23. F. Nakagawa, M. Imae, Y. Hanado, and M. Aida, “Development of multichannel dual-mixer time difference system to generate UTC(NICT),” IEEE Trans. Instrum. Meas. 54(2), 829–832 (2005). [CrossRef]
  24. F.-L. Hong, M. Musha, M. Takamoto, H. Inaba, S. Yanagimachi, A. Takamizawa, K. Watabe, T. Ikegami, M. Imae, Y. Fujii, M. Amemiya, K. Nakagawa, K. Ueda, and H. Katori, “Measuring the frequency of a Sr optical lattice clock using a 120 km coherent optical transfer,” Opt. Lett. 34(5), 692–694 (2009). [CrossRef] [PubMed]
  25. K. Hayasaka, “Synthesis of two-species ion chains for a new optical frequency standard with an indium ion,” Appl. Phys. B 107(4), 965–970 (2012). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


Fig. 1 Fig. 2 Fig. 3
Fig. 4

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited