In 2021, we began designing and building the ROYMAGE (Mobile Ytterbium Optical Clock Applied to Geodesic Exploration) neutral ytterbium optical clock. After caesium, rubidium, strontium and mercury, we are now studying a fifth element at SYRTE, as a new definition of the second takes shape.
As predicted by Einstein as early as 1907, time is coupled to the gravitational potential: this is the so-called gravitational time dilation effect. For an atomic clock, this translates into a coupling (...)
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Transportable ytterbium optical clock (ANR ROYMAGE)
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ANR RYCARD
The ANR PRC RYCARD (RYdberg atoms for Clocks and
Radiation Detection) aims to use Rydberg atoms for ultra-sensitive microwave electric field measurements, with applications to optical clocks -
Horloge à réseau optique basée sur le mercure
Au LNE-SYRTE nous développons une horloge pratiquement unique au monde. Elle est basée sur un échantillon d’atomes de mercure à la température de 20 microkelvin sur lequel nous stabilisons un laser ultraviolet : nous obtenons des incertitudes autour de 5 x 10-17, soit six milliardièmes de seconde par siècle.
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Strontium optical lattice clocks
LNE-SYRTE develops two optical lattice clocks with strontium atoms. They rely on the interrogation, with an "ultra-stable" of about 104 ultra-cold atoms confined in a lattice generated by a powerful trapping laser. Because Sr lattice clocks combine an excellent frequency stability and a very good control of systematic effects, they are a promising candidate for a redefinition of the SI (Système international) second. Sr clocks at LNE-SYRTE now reach a frequency stabilit of 10-15 at 1 second, (...)
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ANR CaOC
The ANR project CaOC (Cavities for optical clocks) aims at combining ultra-stable laser sources with cavity-assisted non-destructive detection methods to improve the frequency stability of optical lattice clocks.
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Mercury optical lattice clock
This project is aiming at developing a new atomic clock based on an optical transition of mercury atoms. Some properties of mercury are similar to these of other atoms considered for atomic clocks such as calcium, strontium or ytterbium, especially the existence of an optical transition with a very narrow natural linewidth. One advantage of mercury is the existence of six abundant and therefore usable isotopes, including two fermions and four bosons. Another advantage is related to the ten (...)
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Optical frequency combs
The optical clocks developed in the laboratory aim at realizing frequency standards made with ultra-stable laser referenced to extremely narrow atomic transitions. The oscillation frequencies of these standards are typically of several hundred Tera-Herz (optical frequencies from near-IR to UV). For such high frequencies, it is of course impossible to use directly the oscillating signal in a time measurement system since there is no electronic system which can go that fast. The traditional (...)
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Spectral Hole Burning
NEW : PhD position available !
More information here Ultra-stable lasers are an important component of optical clocks. As a matter of fact, they are used to probe ultra-narrow atomic "clock" transitions and therefore constitute the local oscillator in these setups. Currently, ultra-stable lasers are realized by locking to very high finesse (typically 106) Fabry-Pérot cavities. These cavities need, of course, to be set in very well controlled vacuum environments, well shielded from (...) -
Optical fiber links
The ultra-stable optical links activity includes the development of the REFIMEVE equipment of excellence, called to join the national roadmap of research infrastructures, and the development of upstream research to further improve performance, enrich the capabilities of fiber optic links, and open up to a wide range of scientific applications.
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IR Lasers stabilized on iodine molecular transitions
SYRTE Laboratory has for several years developed a frequency stabilization project of infrared lasers on atomic vapor, in compact and fibered configurations. This development is based on Telecom photonic components in the vicinity of 1.5 µm, which exhibit superior technological readiness level, unequaled at other wavelength range. The targeted frequency stability is of order of a few 10-14 for the short term and few 10-15 on the medium / long term. This level of performance is typically (...)
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Frequency tranfer by optical link (Mini-DOLL)
In the context of future space missions in fundamental physics (SAGAS, STE-QUEST, OSS, ….) a coherent laser link for clock comparisons, navigation, and data transmission will be essential. This is the long term aim of DOLL (Deep Space Optical Laser Link).
In a terrestrial environment a satellite to ground coherent optical link (Mini-DOLL project) has applications for clock comparison, satellite orbit determination (optical Doppler ranging) and high bandwidth data transmission by phase (...)