arXiv subjects

Paul-Éric Pottie

Publications and source records attributed to Paul-Éric Pottie.

3 recordsLinked to original sources

arXiv2026

Laser Synchronisation Over One Hundred Kilometers With Stability at Picosecond Scale

Large-scale systems, such as very large accelerators used for fundamental research, require the implementation of precise timing and synchronization systems over distances of several kilometers. Femtosecond synchronisation has been reached by the implementation of costly and complex clock distribution systems. However, many devices, such as accelerator diagnostics or detectors for physics at colliders, only require picosecond stability and, in some cases, similar accuracy. An approach that is based on the CERN White Rabbit protocol, deployed on an electronic system capable of generating arbitrary frequencies with Hertz precision, is proposed here. Results of performance tests for the synchronization of a laser system, typically employed as a diagnostic for electron/positron beam polarimetry in accelerators, are provided in this Paper. We demonstrate that the system can synchronize a pulsed laser with picosecond stability over one hundred kilometers on the short-term. The long-term stability over half a day is found to be of 5.5~ps for the 100~km link. The accuracy of the phase difference corresponding to $\pm 20$~ps is obtained. This work paves the way for the deployment of White-Rabbit-based synchronization systems for accelerator components, such as lasers, but also for large-scale detectors.

physics.acc-ph↗

arXiv2025

Precise synchronization of a free-running Rubidium atomic clock with GPS Time for applications in experimental particle physics

We present results of our study devoted to the development of a time correction algorithm needed to precisely synchronize a free-running Rubidium atomic clock with the Coordinated Universal Time (UTC). This R&D is performed in view of the Hyper-Kamiokande (HK) experiment currently under construction in Japan, which requires a synchronization with UTC and between its different experimental sites with a precision better than $100$ ns. We use a Global Navigation Satellite System (GNSS) receiver to compare a PPS and a $10$ MHz signal, generated by a free-running Rubidium clock, to the Global Positioning System (GPS) Time signal. We use these comparisons to correct the time series (time stamps) provided by the Rubidium clock signal. We fit the difference between Rubidium and GPS Time with polynomial functions of time over a certain integration time window to extract a correction of the Rubidium time stamps in offline or online mode. In online mode, the latest fit results are used for the correction until a new comparison to GPS Time becomes available. We show that with an integration time window of around $10^4$ seconds, we can correct the time stamps drift, caused by the frequency random walk noise and the deterministic frequency drift of the free running Rubidium clock, so that the time difference with respect to GPS Time stays within a $\pm5$ ns range in both offline or online correction mode. Presented results could be of interest for other experiments in the field of neutrino physics and multi-messenger astrophysics.

physics.ins-det↗

arXiv2022

Limitations due to residual interference in a fiber-based optical frequency reference at 1.55 $μ$m

We present an experimental investigation of the stability limits specific to optical frequency standards using a fiber-optic architecture and semiconductor lasers. A compact setup composed of a semiconductor laser frequency-locked onto an acetylene transition detected in saturated absorption has been implemented using only fiber-optic components. Fiber optic technology allows compact and reliable solutions for various applications. However, for high sensitivity and stability applications such as metrology, residual reflections induced by optical index inhomogeneities in connectors and fiber-coupled components leading to spurious interference significantly limit performance. We have examined the origin of the interference fringes superimposed on the detected signal and the limitations they cause to the frequency stability of the reference. The effects of temperature and beam power fluctuations are also examined. Our results show that the frequency stability is limited in the 10-13 range by the effect of interference fringes due to use of fiber components.

physics.ins-det↗