An Expander System of High Stable Laser Beam for Cesium Atomic Fountain Clocks

The quality of the cold atoms sample plays an important role to improve the performance of cesium atomic fountain clocks. The preparation of cold atoms sample has a strict requirement for cooling lasers characteristics such as power stability, polarization, collimation, uniformity and verticality. This work implements a design of an expander system of high stable laser beam for the cold atom preparation. The cooling laser characteristics can be adjusted by the design, and the use of non-magnetic materials to avoid the magnetic field on the impact of cold atom. The cold atom sample with the number of 2x10(8) and temperature of 5 mu k was obtained by expander system. The result meets the requirements of the preparation of cold atoms for cesium atomic fountain clocks.