A grating-chip atomic fountain

TL;DR

This paper introduces a compact cold atom fountain utilizing a grating magneto-optical trap, enhancing stability and portability for atomic clock applications through simplified optical setup and improved measurement techniques.

Contribution

It presents a novel, simplified optical configuration for a cold atom fountain using GMOT, achieving longer Ramsey times and better stability in a compact form.

Findings

Achieved Ramsey times up to 100 ms.

Demonstrated improved single-shot stability.

Fringe linewidth of 5 Hz.

Abstract

Cold atom fountain clocks provide exceptional long term stability as they increase interrogation time at the expense of a larger size. We present a compact cold atom fountain using a grating magneto-optical trap (GMOT) to laser cool and launch the atoms in a simplified optical setup. The fountain is evaluated using coherent population trapping and demonstrates improved single-shot stability from the launch. Ramsey times up to 100 ms were measured with a corresponding fringe linewidth of 5 Hz. This technique could improve both short- and long-term stability of cold atom clocks whilst remaining compact for portable applications.