Atomic Frequency Standards

The Atomic Frequency Standards group at INRiM generates and maintains in Italy the unit of Time in the International System of Units (SI), i. e. the second (s). This is based on the hyperfine  transitions of the ground state of the Caesium 133 atom and it is realized by a cryogenic Cs-fountain atomic clock.

We conduct metrological research to develop better atomic clocks and better dissemination techniques of the unit of Time. We are developing more precise atomic clocks based on optical transitions of cold neutral atoms of ytterbium (Yb) and strontium (Sr) trapped in lattice potentials at the magic wavelength, and we have realized as well compact atomic clocks based on Rubidium vapor cells with unprecedented performance. We are investigating the realization of chip-scale clocks. We are studying and developing alternative techniques for the dissemination of frequency signals on a continental scale by using optical fibers. We apply advanced simulation techniques to support these activities.

All these tools enable the measurement of time and frequency at always improving precision, and are definitely opening the door to new experiments in fundamental physics, spectroscopy, radioastronomy and geodesy.

Main page on the INRiM website

(Picture by Fabio Bucciarelli)