Details
| Original language | English |
|---|---|
| Pages (from-to) | 307-321 |
| Number of pages | 15 |
| Journal | Metrologia |
| Volume | 54 |
| Issue number | 3 |
| Publication status | Published - 5 Mar 2017 |
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
- Atomic frequency standards, Local oscillator noise, Quantum projection noise, Servo optimisation
ASJC Scopus subject areas
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In: Metrologia, Vol. 54, No. 3, 05.03.2017, p. 307-321.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - On-line estimation of local oscillator noise and optimisation of servo parameters in atomic clocks
AU - Leroux, Ian D.
AU - Scharnhorst, Nils
AU - Hannig, Stephan
AU - Kramer, Johannes
AU - Pelzer, Lennart
AU - Stepanova, Mariia
AU - Schmidt, Piet Oliver
PY - 2017/3/5
Y1 - 2017/3/5
N2 - 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.
AB - 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.
KW - Atomic frequency standards
KW - Local oscillator noise
KW - Quantum projection noise
KW - Servo optimisation
UR - http://www.scopus.com/inward/record.url?scp=85020851204&partnerID=8YFLogxK
U2 - 10.1088/1681-7575/aa66e9
DO - 10.1088/1681-7575/aa66e9
M3 - Article
AN - SCOPUS:85020851204
VL - 54
SP - 307
EP - 321
JO - Metrologia
JF - Metrologia
SN - 0026-1394
IS - 3
ER -