Rubidium Atom Based 778-Nm Secondary Optical Clock as Laboratory Time Base

Constantly inspecting rubidium secondary optical clock is essential due to the impact on both the issue ofatom collision shift in academic research and the industrial applications. However, our previous investigationshowed [1] that the helium atom in atmosphere could change the frequency of cesium atom 6S-8S transitionin glass cell. Therefore, to understand how much would the helium atoms in atmosphere influence thefrequency of glass cell-based rubidium clock is very important and this is the goal of this one-year project.The realization of two optical clocks (822-nm cesium stabilized and 778-nm rubidium stabilized), togetherwith our Ti:sapphire comb laser, can greatly save the budget of buying cesium atomic beam clock (aroundNTD 4 millions) since we had proved that the stability and accuracy of the secondary optical clock in ourlaboratory could reach the level of cesium clock. The success of this one-year project will bring us theaccurate time base from radio frequency to micro-wave frequency up to optical frequency, which greatlyhelps us for some other high-precision quantum optics project that would be proposed in two years later.