Frequency comb bridges the gap between frequency standards and the optical domain, for molecular spectroscopy and astrophysics
As part of the Wallonia Plan de Relance and the SPACE Excellence Platform, the LAS&O platform has just acquired a new frequency comb, an instrument for measuring the frequency of light with the precision of atomic clocks.
A frequency comb is a mode-locked laser whose repetition frequency f_rep and the frequency associated with the offset between carrier and envelope f_0 have been stabilized. It is therefore a polychromatic light source with a stable, structured spectrum. It is often described as the emission of thousands of phase-locked lasers, the frequency of each of these lasers being written as f_n = n*f_rep +f_0, where n is an integer.
The quantities f_rep and f_0 are two frequencies in the radiofrequency domain, so they can be disciplined on an atomic clock (Rubidium, Hydrogen laser, Strontium), transposing these frequency standards into the optical domain.
This tool will be used within the LAS&O platform to determine the frequency of lasers emitting in the near infrared and greatly improve their stability by controlling them on the comb.
These lasers could be used for various metrological applications, such as measuring the spectral signatures of molecules of astrophysical interest.
This tool will therefore enable us to break a scientific deadlock, and the results obtained will provide support for various space missions.
