Design of an atom source collimator for a compact frequency-stabilized laser

A concise laser system for optically pumped cesium beam clocks is presented. The laser’s frequency is locked by a fluorescence signal, produced by the interaction between a cesium atomic beam and laser. A cesium oven with a longer atom source collimator, formed by an array of channels, was used to reduce the divergence angle of the cesium atomic beam. The size of the cesium source collimator is 4  mm×0.6  mm, and the cesium expenditure rate is 2.4×10−1  g per year. A dense cesium atomic flux was used to interact with the laser to generate a fluorescence signal when the oven heating temperature is not too high. The cesium beam tube could have a longer lifetime. The optical structure of the laser system is compact. The measured frequency stability of the laser is ∼4×10−11 at 10,000 s when the laser frequency is locked in the F=4→F′=5 transition of the cesium D2 line. The design of an atom oven and atom source may be used in other atomic beam clocks to improve their performance.