Gigahertz self-sustained pulsations in chirped distributed feedback fiber lasers

In this paper we present a model to analyze the dynamics of erbium doped chirped-grating distributed feedback (DFB) fiber lasers. Our results show that an asymmetrically chirped DFB fiber laser can undergo sustained self-pulsations at frequencies >5 GHz. These pulsations result from the beating between two asymmetric longitudinal modes with different frequencies but similar gains.