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Address: No.18,Bei San Huan
Dong Lu,Chaoyang
Dist,Beijing,P.R.China, 100013



New Frequency Standard, Strontium Lattice Optical Clock

An optical lattice clock based on ultra narrow atomic transition of neutral strontium atoms is being built at this lab. The strontium atoms are cooled to a temperature of a few micro-Kelvin by two stages of laser cooling. They are then loaded into a 1-dimentional optical lattice. An ultra narrow linewidth laser is used as a local oscillator to probe the atoms. An error signal is extracted from the fluorescence to lock the laser frequency to the atomic transition.



Optical clocks have potential for improvement in precision over cesium microwave clocks. According to the Report of the 18th Meeting of Consultative Committee for Time and Frequency(CCTF), optical clocks are advised to be considered as the new definition of the SI unit time (second).

The objective of this project is to build an optical lattice clock based on 1S0-3P0 transition of 87Sr. The systematic error is expected to be controlled below 1E-15. The frequency of the clock transition will be measured by the current existing primary time and frequency standard. The clock can also be applied in fundamental physics field, to test time variations of physical constants for example.