Frequency-Stability Performances of the Pulsed Optically Pumped Rubidium Clock: Recent Results and Future Perspectives

This paper presents new results obtained with a laboratory prototype of a pulsed optically pumped frequency standard based on a vapor cell containing⁸⁷Rbdiluted in a buffer gas. A frequency stability of about1.2 × 10⁻¹²τ-1/2$has been measured, and the value of$3 × 10⁻¹⁵$for integration times of$10⁵$s has been achieved (drift removed data). These performances show that a suitable implementation of this standard can lead to a compact vapor-cell clock with a very interesting short- and medium-term frequency stability and, consequently, may be of great interest in radio-navigation systems. We also present some possible improvements of the pulsed technique.