On-line estimation of local oscillator noise and optimisation of servo parameters in atomic clocks

verfasst von: Ian D. Leroux, Nils Scharnhorst, Stephan Hannig, Johannes Kramer, Lennart Pelzer, Mariia Stepanova, Piet Oliver Schmidt
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.
Organisationseinheit(en): Institut für Quantenoptik
SFB 1227: Designte Quantenzustände der Materie (DQ-mat)
Externe Organisation(en): Physikalisch-Technische Bundesanstalt (PTB)
National Research Council of Canada
Typ: Artikel
Journal: Metrologia
Band: 54
Seiten: 307-321
Anzahl der Seiten: 15
ISSN: 0026-1394
Publikationsdatum: 05.03.2017
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Ingenieurwesen (insg.)
Elektronische Version(en): https://doi.org/10.1088/1681-7575/aa66e9 (Zugang: Offen)

BibTeX

@article{0765b09d64da41c2977754d043e2079d,
title = "On-line estimation of local oscillator noise and optimisation of servo parameters in atomic clocks",
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",
author = "Leroux, {Ian D.} and Nils Scharnhorst and Stephan Hannig and Johannes Kramer and Lennart Pelzer and Mariia Stepanova and Schmidt, {Piet Oliver}",
year = "2017",
month = mar,
day = "5",
doi = "10.1088/1681-7575/aa66e9",
language = "English",
volume = "54",
pages = "307--321",
journal = "Metrologia",
issn = "0026-1394",
publisher = "IOP Publishing Ltd.",
number = "3",
}