EMISSION DEPENDENCE ON LENGTH IN A 1.48-MU-M PUMPED ERBIUM-DOPED LASER WITH AN ALL-FIBER CONFIGURATION

We report a study on the main features of a 1.48-mu m pumped erbium-do ped-fiber laser, such as threshold pump power, output power, and slope efficiency. In particular we have focused on its dependence on active fiber length. We employed an all-fiber laser configuration, which inc luded mirrors directly coated onto the polished fiber endfaces. Launch ed pump power and laser output power were introduced and extracted, re spectively from the laser cavity by means of couplers. Our measurement s show the existence of an optimum erbium-doped-fiber length, where th reshold power reaches minimum and output power maximum.