Automatic laser control for a Sr-88(+) optical frequency standard

作者：Barwood G P^*; Gill P; Huang G; Klein H A

来源：Measurement Science and Technology, 2012, 23(5): 055201.

DOI：10.1088/0957-0233/23/5/055201

• ion cooling
• time and frequency
• computer control systems

Optical frequency standards, based on the 674 nm S-2(1/2)-D-2(5/2) transition in a single cold trapped Sr-88(+) ion, are being characterized at the UK National Physical Laboratory. Routine operation is required for measurement campaigns over several days and there is also a long-term requirement for unattended operation in remote environments, such as on a satellite or at a spacecraft tracking ground station. Software algorithms have been developed which enable the automatic relocking of multiple extended cavity diode lasers to optical cavities following out-of-lock errors. Additional algorithms are used to monitor and control auxiliary distributed feedback diode lasers by means of a wavemeter. Using this control system, unattended operation for more than 60 h has been demonstrated. Preliminary results are presented giving a single-trap relative frequency stability of 2.5 x 10(-16) at tau = 4000 s. This capability paves the way for a reliable Sr+ ion-trap-based optical standard capable of operating remotely for extended periods.

• 出版日期2012-5