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

Autor: Nils Scharnhorst, Johannes Kramer, Mariia Stepanova, Ian D. Leroux, Piet O. Schmidt, Lennart Pelzer, Stephan Hannig
Rok vydání: 2017
Předmět:
Dewey Decimal Classification::500 | Naturwissenschaften::550 | Geowissenschaften
Optimization
Atomic clocks
Frequency standards
Atomic Physics (physics.atom-ph)
Local oscillator
FOS: Physical sciences
Quantum projection noise
Linear prediction
01 natural sciences
Stability (probability)
Noise (electronics)
Physics - Atomic Physics
010305 fluids & plasmas
Servo optimisation
Optimal linear prediction
Control theory
Atomic frequency standards
0103 physical sciences
ddc:550
Parameter estimation
010306 general physics
atomic frequency standards
Scaling
Local oscillator frequencies
Physics
local oscillator noise
quantum projection noise
General Engineering
Spectral properties
Atomic clock
Frequency fluctuation
servo optimisation
Atomic number
Local oscillator noise
Local oscillators
Atomic physics
Optimisations
Servo
Zdroj: Metrologia 54 (2017), Nr. 3
ISSN: 1681-7575
0026-1394
DOI: 10.1088/1681-7575/aa66e9
Popis: For atomic frequency standards in which fluctuations of the local oscillator (LO) frequency are the dominant noise source, we examine the role of 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.
16 pages, 7 figures. Added discussion of servo's spectral response and of phase-stabilization vs frequency stabilization. Results unchanged from first version
Databáze: OpenAIRE
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