2026/08/06 by Xiaomin Qin, Suyang Wei, Haijun Chen +8
Physics and Astronomy · #physics.atom-ph #quant-ph
12 pages, 5 figures
arxiv created 2026/08/06 · arxiv updated 2026/08/07
Compact cesium beam clocks are major frequency references for deployable timing systems. However, further improvement of their short-term frequency stability is limited by the clock signal-to-noise ratio (SNR). Although two-laser optical pumping can increase the effective atomic utilization, the achievable clock SNR has long been limited by laser-induced frequency-to-amplitude noise conversion. Here, we demonstrate a compact dual-Faraday-laser-pumped (DFP) Cs beam clock enabled by a low-frequency-noise atom-referenced laser architecture. The intracavity Faraday anomalous dispersion optical filter provides inherent alignment to the Cs D2 resonances, while modulation transfer spectroscopy offers suppressed frequency noise and drift. The resulting laser system supports robust turnkey operation with a Lorentzian linewidth of 2.12 kHz. The DFP Cs clock achieves a clock SNR of 46,365 in a 1-Hz bandwidth and a fractional Allan deviation of 7.7× 10-13/√τ , with Hadamard deviation reaching 7.7× 10-15 at 10,000 s. This work pushes the fractional frequency stability of a compact Cs beam clock into the 10-13/√τ regime, providing a pathway toward high-performance Cs frequency references for field-deployable precision timing, navigation, and synchronization.