DocumentCode
2667306
Title
Improvement in accuracy of a single 40Ca+ optical clock towards the 10−15 level using a magnetic shield
Author
Matsubara, Kensuke ; Li, Ying ; Nagano, Shigeo ; Ito, Hiroyuki ; Kajita, Masatoshi ; Kojima, Reiko ; Hanado, Yuko ; Hayasaka, Kazuhiro ; Hosokawa, Mizuhiko
Author_Institution
Space-Time Stand. Group, Nat. Inst. of Inf. & Commun., Tokyo, Japan
fYear
2011
fDate
2-5 May 2011
Firstpage
1
Lastpage
4
Abstract
We report a frequency measurement of a single 40Ca+ optical clock towards the 10-15 uncertainty level. In contrast with our previous measurement, in which the accuracy was limited by line broadening due to the magnetic field fluctuation, the use of a magnetic shield significantly reduced the spectrum linewidth of the clock transition. By a frequency comparison to an 87Sr lattice clock, an Allan deviation of 7 × 10-16 was observed at an averaging time of 103 seconds. We preliminarily measured the clock transition frequency to be 411 042 129 776 397 (3) Hz with respect to the SI definition of the second. Further measurements are executed aiming at an accuracy of low parts in the 10-15 level.
Keywords
atomic clocks; frequency measurement; magnetic fields; magnetic shielding; Allan deviation; clock transition frequency measurement; line broadening; magnetic field fluctuation; magnetic shield; optical clock; spectrum linewidth; Clocks; Frequency measurement; Laser stability; Laser transitions; Measurement by laser beam; Optical variables measurement; Uncertainty;
fLanguage
English
Publisher
ieee
Conference_Titel
Frequency Control and the European Frequency and Time Forum (FCS), 2011 Joint Conference of the IEEE International
Conference_Location
San Fransisco, CA
ISSN
1075-6787
Print_ISBN
978-1-61284-111-3
Type
conf
DOI
10.1109/FCS.2011.5977880
Filename
5977880
Link To Document