Laser source having a plurality of spectral lines separated by a determined spectral interval

A laser source for emitting at least one multispectral light emission having a plurality of spectral lines separated by a determined spectral interval, the laser source comprising:

• a bank of lasers configured to emit light emissions at a plurality of emission frequencies;
• an optical ring resonator having a free spectral range equal to the determined spectral interval, the optical ring resonator being arranged optically downstream of the bank of lasers to receive the multispectral light emission;
• a photodetector arranged optically downstream of the optical ring resonator to establish a control signal representative of the multispectral light emission transmitted through the ring resonator;
• a plurality of modulators, each modulator being associated with a respective laser of the bank and configured to apply to said laser a periodic modulation signal having a modulation frequency distinct from the modulation frequencies of the other modulators, such that the control signal established by the photodetector contains a component at the modulation frequency of each laser;
• and
• a locking device configured to process the control signal, to extract for each laser the component at its associated modulation frequency, and to generate an adjustment command that reduces a misalignment between the emission frequency of a laser and a resonant frequency of the optical ring resonator, thereby controlling the spectral interval between adjacent spectral lines of the multispectral light emission.