On-line estimation of local oscillator noise and optimisation of servo parameters in atomic clocks
Open Access
- 5 April 2017
- journal article
- research article
- Published by IOP Publishing in Metrologia
- Vol. 54 (3), 307-321
- https://doi.org/10.1088/1681-7575/aa66e9
Abstract
For atomic frequency standards in which fluctuations of the local oscillator (LO) frequency are the dominant noise source, we examine the role of the the servo algorithm that predicts and corrects these frequency fluctuations. We derive the optimal linear prediction algorithm, showing how to measure the relevant spectral properties of the noise and optimise servo parameters while the standard is running, using only the atomic error signal. We find that, for realistic LO noise spectra, a conventional integrating servo with a properly chosen gain performs nearly as well as the optimal linear predictor. Using simple analytical models and numerical simulations, we establish optimum probe times as a function of clock atom number and of the dominant noise type in the local oscillator. We calculate the resulting LO-dependent scaling of achievable clock stability with atom number for product states as well as for maximally-correlated states.Keywords
Other Versions
Funding Information
- Deutsche Forschungsgemeinschaft (CRC 1128, CRC 1227)
- EMPIR (15SIB03 OC18)
- Alexander von Humboldt-Stiftung
This publication has 43 references indexed in Scilit:
- Optical Spectrum Analyzer with Quantum-Limited Noise FloorPhysical Review Letters, 2013
- Near-Heisenberg-Limited Atomic Clocks in the Presence of DecoherencePhysical Review Letters, 2013
- A steady-state superradiant laser with less than one intracavity photonNature, 2012
- Entanglement-assisted atomic clock beyond the projection noise limitNew Journal of Physics, 2010
- Laser frequency stabilization to a single ionJournal of Physics B: Atomic, Molecular and Optical Physics, 2005
- Optimum measurement strategies for trapped ion optical frequency standardsJournal of Physics B: Atomic, Molecular and Optical Physics, 2004
- Stability of Atomic Clocks Based on Entangled AtomsPhysical Review Letters, 2004
- Optimal Quantum ClocksPhysical Review Letters, 1999
- Squeezed spin statesPhysical Review A, 1993
- Spin squeezing and reduced quantum noise in spectroscopyPhysical Review A, 1992