Cavity configuration study of an EDFL system

In this paper, experimental results are presented comparing the effects of co-propagation and counter-propagation configurations on the erbium-doped fiber laser (EDFL) output. Counter-propagating system refers to the configuration where pump light is traveling along the fiber in a direction opposite to that of the oscillation light, whereas co-propagating has the laser pump light in the same direction as the oscillation. This paper emphasizes on the configuration effects on the system´s output power, amplified spontaneous emission (ASE), side mode suppression ratio (SMSR) and tuning range for a tunable system, at several different erbium doped fiber lengths. An observation was also made for both configurations in a fixed-wavelength fiber laser system