Temperature Coefficient Optimization of the Physics Package of Rubidium Atomic Clock

Abstract

The vapor-cell rubidium atomic clock is widely used in Global Navigation Satellite System (GNSS) and telecommunications. The sensitivity of temperature is one of the most important factors affecting the performance of rubidium Atomic Frequency Standards (RAFS). It plays a significant role in the long-term frequency stability of the rubidium atomic clock, and largely depends on the Physics Package (PP). In this paper, we attempt to reduce the temperature sensitivity of RAFS in a specific environment of vacuum and extraterrestrial temperature. We achieve this by studying the theory of light shift, collision shift, and magnetic frequency shift in RAFS. By combining this with our engineering expertise, we have proposed a single method on three parameters to optimize the temperature coefficient of PP of the rubidium atomic clock, which can not only optimize the temperature coefficient of PP, but can also improve the long-term frequency stability of the rubidium atomic clock. Some related experiments, by the proposed method, further demonstrate a significant reduction in the temperature coefficient of PP, suggesting that the performance of RAFS can be improved.