In atomic clocks, the frequency source is a Hydrogen, Rubidium or Cesium atom. These atoms have the unique ability to generate high-precision frequency radiation when one of their electrons changes from one energy level to another. Since all atoms behave in the same exact way and never wear out, the electromagnetic radiation produced from any clock is always the same. Atomic clocks’ precision and stability make them the most accurate in the world.



Rubidium clocks

Thanks to SpectraTime, Orolia benefits from over 15 years of expertise in the development of Rubidium clocks. These clocks offer such a high level of precision that their accuracy is almost 100 times better than one-billionth of a second. That’s like knowing the size of a grain of sand compared to the circumference of the earth! They also offer similar levels of stability on the short-term scale.

Spatial Rubidium clocks	Industrial Rubidium clocks

Hydrogen maser clocks

Hydrogen masers are the most precise clocks in the world, offering the highest short-term stability, up to 100 times better than a Rubidium clock. They are known as masers since they operate similarly to lasers but generate microwave radiation instead of light radiation.
There are two different types of maser clocks: active masers and passive masers.

Active maser clocks	Passive maser clocks

© crédit photos OROLIA

Orolia's hyper-accurate clocks : the beating heart of Galileo Orolia's Rubididum Atomic Clock for Galileo : a year of in-orbit experience Precision timekeeping for Europe : ESA’s and Orolia's vital contribution

Rubidium clocks Hydrogen maser clocks