All-Optical Integrated rubidium Atomic Clock

We report on progress in the development of an All-Optical Integrated Micro-Primary Atomic Clock (AO-IMPAC). The operattion of the clock is based on an inhomogeneously broadened rubidium optical transition used for stabilization of a Kerr optical frequency comb generated in a high-Q whispering gallery mode (WGM) microresonator. We have demonstrated the initial operation of this clock built in a physics package with dimensions 5 × 6 × 1.2 cm. The clock´s long term stability approaches 3 × 10^-13 at about 2 × 10⁴ s integration time. The measured value is limited by the noise floor of the measurement setup.