Optoelectronic nibbling of laser linewidth using a Brillouin-assisted optical phase-locked loop

Gwennaël Danion (1) , Marc Vallet (1) , Ludovic Frein (1) , Pascal Szriftgiser (2) , Mehdi Alouini (1)

1 FOTON - Institut des Fonctions Optiques pour les Technologies de l'informatiON
2 PhLAM - Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523

We demonstrate that the implementation of phase-locked loop forbidding multimode operation of a long Brillouin resonator also leads to a dramatic reduction of the optical phase noise of the pump itself. In the case of a continuous Er,Yb:glass laser, a reduction by more than 90 dB at 100 Hz of the carrier is observed. This yields an optical linewidth estimated narrower than 2 Hz for the pump laser. The method being independent of the laser wavelength, it can be applied to almost any laser.

Domaines: Physique Générale [physics.gen-ph]; Instrumentations et Détecteurs [physics.ins-det]

Gwennaël Danion, Marc Vallet, Ludovic Frein, Pascal Szriftgiser, Mehdi Alouini. Optoelectronic nibbling of laser linewidth using a Brillouin-assisted optical phase-locked loop. 2018. ⟨hal-01871973⟩