CW-pumped polarization-maintaining Brillouin fiber ring laser: II. Active mode-locking by phase modulation

Jean Botineau (1) , Gérard Cheval (1) , Carlos Montes (1)

1 LPMC - Laboratoire de physique de la matière condensée

Stimulated Brillouin backscattering in a cw-pumped long optical polarization-maintaining fiber ring cavity excites spontaneous stable mode-locking. But the shortest pulses allowed by the Brillouin gain bandwidth imply an active mode-locking, which we have achieved by using a phase modulator inside the ring. The experiment is carried out in the infrared at 1.319 lm, and in narrow frequency domains, close to N integer multiples of the ring FSR, we observe two type of mode-locking: either a maximum compression of the Brillouin solitons, or a stable splitting into N equally spaced pulses. Case N = 3 is more detailed. Experiment implies a slight polarization modulation by the phase modu- lation. Simulations carried out through the coherent three-wave model are in very good agreement for both mode-lock- ing mechanisms. Introduction of a small amplitude modulation together with the intra-cavity phase modulation satisfactorily explains the stable splitting domain as well as the compression domain.

Domaines: Optique [physics.optics]; Formation de Structures et Solitons [nlin.PS]

Jean Botineau, Gérard Cheval, Carlos Montes. CW-pumped polarization-maintaining Brillouin fiber ring laser: II. Active mode-locking by phase modulation. Optics Communications, 2006, 257, pp.311-318. ⟨10.1016/j.optcom.2005.07.049⟩. ⟨hal-00460392⟩