Development of an optically pumped Cs frequency standard at theNRLM

Describes development of an optically pumped Cs frequency standard aiming at a primary frequency standard. Using this laboratory-type standard, a Ramsey resonance spectrum was observed. It has been shown that a laser power of about 1 mW is almost sufficient for two-frequency optical pumping. It has also been shown that the C-field strength can be measured using Zeeman coils by establishing a population difference among the Zeeman sublevel with σ⁺ polarized laser light