Activities Time-Frequency:
Workforce: 9with: 6 permanents, 3 non-permanent
MARSEILLE, France
Our research activity is based on the interaction of one or several lasers with ions stored in a radiofrequency trap, aiming at experiments in the domain of time and frequency metrology but also the study and control of the dynamics of a large and cold atomic sample (a non-neutral plasma). Several experimental set-ups combine trapped ions and several narrow-linewidth lasers, in particular a lab-built Ti:Sa laser at 729 nm which allows to probe the ultra-narrow optical transition in calcium ions. For metrology applications, we use a double linear radiofrequency trap which can store single ions as well as large ion clouds. Its original properties are the storage of ions in potentials of different geometry, and the transport of laser-cooled ions between those zones using shortcuts to adiabaticity.
In the domain of time and frequency metrology, ion traps take a special place due to their unique possibility to access the regime of strong confinement which offers advanced control of spectroscopic properties. We pursue two routes:
- the interrogation of the electric quadrupole transition of Calcium Ca+ ions at 729 nm using coherent processes with two or three photons in order to make high-precision measurements. Depending on the interrogation protocol, different atomic samples (from one to many ions) will be probed. We work on novel interrogation protocols which allow to eliminate Doppler broadening in the process.
- we explore critical parameters of microwave atomic clocks operating with large ion clouds for space application. We are interested in devices like JPL's Deep Space Atomic clock (DSAC) .
Contribution to:
Refimeve+
International collaborations:
Aarhus Univesitet, Aarhus, Danemark (équipe du Prof. M. Drewsen)
Universität des Saarlandes, Saarbrücken, Allemagne (équipe de la Prof. G. Morigi)
University of Delaware, USA (équipe de la Prof. M. Safronova)
Crédit photo : Cyril FRESILLON / PIIM / FIRST-TF / CNRS Photothèque.
Crédit photo : Cyril FRESILLON / PIIM / FIRST-TF / CNRS Photothèque.
Crédit photo : Cyril FRESILLON / PIIM / FIRST-TF / CNRS Photothèque.
Crédit photo : Cyril FRESILLON / PIIM / FIRST-TF / CNRS Photothèque.
Crédit photo : Cyril FRESILLON / PIIM / FIRST-TF / CNRS Photothèque.
Expertise :
- Oscillators
- Optical oscillators, lasers
- Lasers locked to a Fabry-Pérot cavity• Lasers frequency-locked at different wavelengths between 400 and 870 nm, various locking schemes, very high-finesse cavity, ultra-stable cavity
Regarding high-finesse cavities: simulation and design, assembly of spacer and mirrors, advanced cleaning procedures, optical contact - Lasers locked to an atomic or molecular line• Lasers locked to atomic line by saturated absorption set-up
- Frequency combs• Frequency comb with different outputs between 780 and 1550 nm, frequency comb offset- free operation, noise characterization down to 10-14 (limited by local oscillator)cross-correlation measurementsRefimeve+ partner
- Laser sources• Cw laser sources at various visible wavelength : 397 nm, 729 nm, 866 nm, 794 nm Laser diodes (also in external cavities), Titanium-sapphire Ti:Sa lasers (one home-built)
femtosecond laser (frequency comb) at 1542 nm
- Lasers locked to a Fabry-Pérot cavity• Lasers frequency-locked at different wavelengths between 400 and 870 nm, various locking schemes, very high-finesse cavity, ultra-stable cavity
- Optical oscillators, lasers
- Atomic references
- Micro-wave clocks and subsystems
- Microwave ion clocks• Critical parameters and interrogation protocols for microwave clocks with trapped ions
- Optical clocks and subsystems
- Optical ion clocks• Realisation of clock laser at 729 nm
Novel interrogation protocols (also in the THz domain)
- Optical ion clocks• Realisation of clock laser at 729 nm
- Micro-wave clocks and subsystems
- Specific methods of time-frequency metrology
- Noise
- Phase noise, PLL
- Intensity noise• Intensity noise correction via PID
- Short term stability, long term stability• Measurements of short-term and long-term frequency stability by dedicated instrumentation
- Systematics, Accuracy, Calibration
- Systematics in atom-light interaction• Computation and evaluation of a complete error budget for a frequency standard
Control of micromotion of trapped ions
Control of systematic effects in the experimental probing of trapped ions
Absolute frequency measurements (between 729 and 1550 nm)
- Systematics in atom-light interaction• Computation and evaluation of a complete error budget for a frequency standard
- High resolution spetroscopy
- Atomic spectroscopy• Interrogation of a single atom (ion)
Dark resonances, CPT
Multi-photon coherent spectroscopy
- Atomic spectroscopy• Interrogation of a single atom (ion)
- Noise
Connected Sectors:
- Fundamental science
- Fundamental metrology• Novel, high-resolution interrogation protocols of radiofrequency trapped ions
- Arts, Languages, human and social sciences
- History of science, philosophy• Ancient theories of vision knowledge about Fresnel work and its context.