LAS&O - Measuring the frequency of light with the precision of atomic clocks
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The frequency comb, an optical metrology tool for molecular spectroscopy (and astrophysics)
A frequency comb is a polychromatic light source with a stable, structured spectrum.
It 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 often described as the emission of thousands of phase-locked lasers, the frequency of each of which can be 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 maser, Strontium), transposing these frequency standards into the optical domain.
Acquired thanks to the Wallonia Recovery Plan in the framework of the SPACE Excellence Platform, 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 slaving them to the comb.
These lasers can be used for various metrological applications, such as measuring the spectral signatures of molecules of astrophysical interest.
This tool will help to break a scientific deadlock, and the results obtained will provide support for various space missions.
Picture credit : LAS&O