Improvement in accuracy of a single 40Ca+ optical clock towards the 10−15 level using a magnetic shield
- Resource Type
- Conference
- Authors
- Matsubara, Kensuke; Li, Ying; Nagano, Shigeo; Ito, Hiroyuki; Kajita, Masatoshi; Kojima, Reiko; Hanado, Yuko; Hayasaka, Kazuhiro; Hosokawa, Mizuhiko
- Source
- 2011 Joint Conference of the IEEE International Frequency Control and the European Frequency and Time Forum (FCS) Proceedings Frequency Control and the European Frequency and Time Forum (FCS), 2011 Joint Conference of the IEEE International. :1-4 May, 2011
- Subject
- Communication, Networking and Broadcast Technologies
Components, Circuits, Devices and Systems
Computing and Processing
Signal Processing and Analysis
Robotics and Control Systems
Power, Energy and Industry Applications
Frequency measurement
Clocks
Laser stability
Uncertainty
Laser transitions
Measurement by laser beam
Optical variables measurement
- Language
- ISSN
- 2327-1914
2327-1949
1075-6787
We report a frequency measurement of a single 40 Ca + 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 87 Sr lattice clock, an Allan deviation of 7 × 10 −16 was observed at an averaging time of 10 3 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.