Primary optical signals amplifying device, has single mode doped optical fiber with single mode core surrounded by doped region to amplify primary optical signals received in presence of secondary optical signals

The device has a laser diode (3) to deliver secondary single mode optical signals with desired wavelength. A single mode doped optical fiber (1) has a single mode core surrounded by a doped region. The fiber is arranged to present a small overlap between the doped region and the secondary optical signals. The fiber is arranged to amplify primary optical signals received in the presence of the secondary optical signals. Un dispositif (D), d'amplification de signaux optiques primaires, comprend des moyens de pompage optique (3) délivrant des seconds signaux optiques monomodes de longueur d'onde choisie, et au moins un premier guide d'onde optique monomode (1) comportant une région dopée (6), et agencé de manière à présenter un recouvrement faible entre sa région dopée (6) et les signaux optiques secondaires et à amplifier des signaux optiques primaires reçus en présence desdits signaux optiques secondaires.