Optical frequency standard based on a single 40Ca+
- 938 Downloads
Research on the development of the optical frequency standard based on trapped and cold 40Ca+ with the 4s 2S1/2-3d 2D5/2 clock transition at 729 nm is reported. A single calcium ion was trapped and laser cooled in the Paul trap and stay in trap for more than 15 days. The linewidth of a 729 nm laser was reduced to less than 10 Hz by locking to a cavity for longer than 50 hours uninterruptedly. The overall systematic uncertainty of the clock transition has been characterized to be better than 6.5×10−16. The absolute frequency of the clock transition was measured at 10−15 level using an optical frequency comb referenced to a Hydrogen maser, which was calibrated to the SI second through the global positioning system (GPS). The frequency value was 411042129776393.0(1.6) Hz after the correction of the systematic shifts.
Keywordsoptical frequency standard single calcium ion systematic uncertainty absolute frequency measurement
- 12.The International Committee for Weights and Measures (CIPM). Recommendation 2 (c2-2009)-(CIPM): Updates to the list of standard frequenciesGoogle Scholar
- 30.Madej A A, Bernard J E, Dubé P, et al. Absolute frequency of the 88Sr+ 5s 2S1/2-4d 2D5/2 reference transition at 445 THz and evaluation of systematic shifts. P Phys Rev A, 2004, 70: 01250Google Scholar
- 31.Itano W M. External-field shifts of the Hg optical frequency standard. J Res NIST, 2000, 105: 829–837Google Scholar
- 36.Bureau International des Poids et Mesures (BIPM). Circular T, May & June 2010, http://www1.bipm.org/en/scientific/tai/timeftp.html Google Scholar
- 37.Matsubara K, Li Y, Nagano S, et al. Absolute frequency measurement of the 40Ca+ clock transition using a LD-based clock laser and UTC(NICT). IEEE Int Freq Contr Symp, 2009, 1 & 2: 751–755Google Scholar
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.