Integrated pulsed optically pumped Rb atomic clock with frequency stability of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:msup><mml:mn>10</mml:mn><mml:mrow><mml:mo>−</mml:mo><mml:mn>15</mml:mn></mml:mrow></mml:msup></mml:math>

Abstract

Pulsed optically pumped (POP) Rb atomic clock is considered to be a powerful technique for the Rb atomic clock due to the capability of light-shift mitigation and atomic spectroscopy narrowing. Relevant investigations are conducted over two decades, however, no integrated prototype of such a kind of clock has been reported yet. Here, we present an integrated prototype of the POP Rb atomic clock and quantitatively characterize its physical properties. The atomic clock shows a short-term fractional frequency stability of $2.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}/\sqrt{\ensuremath{\tau}}$ (where $\ensuremath{\tau}$ is the averaging time), and comes to $2.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$ with 40 000 s averaging (drift removed) under atmospheric conditions. Physical effects contributing to the long-term frequency stability are carefully analyzed and cavity-pulling shift is identified as the leading limit. The techniques presented here enable realizing a low ${10}^{\ensuremath{-}15}$ level vapor-cell atomic clock under atmospheric conditions, which could benefit a wide range of terrestrial applications, such as quantum communication, decimeter-level terrestrial positioning.

Topics & Concepts