Investigation of an Ultra High Signal-to-noise Ratio Physics Package for the Rubidium Atomic Clock

Abstract

Driven by the demand for satellite navigation and deep space exploration, the performance of lamp-pumped rubidium atomic clock has been greatly improved, and its short-term frequency stability has reached the level of a small coefficient of 10-13τ -1/2. To further improve the frequency stability of rubidium clock and explore its performance limit, this article is based on the redesign and experimental verification of the structure of the physical package (PP, Φ40 microwave cavity) in the early stage, with a comprehensively optimized design of the optical system of PP, the performance of the spectral lamp and pumping light has been enhanced. Finally, the SNR of PP has been significantly increased. The test and evaluation results showed that the contribution of the shot noise of the newly designed PP to the frequency stability of rubidium clock is 4.2×10-14τ -1/2. The results of this research lay the foundation for the short-term stability of rubidium clocks to achieve 5×10-14τ -1/2, and the long-term stability to break through 1×10-15.

Keywords

• rubidium atomic clock
• physics package
• signal-to-noise ratio
• spectral lamp
• frequency stability