Gigahertz self-sustained pulsations in chirped distributed feedback fiber lasers

摘要

In this paper we present a model to analyze the dynamics of erbiumdoped chirped-grating distributed feedback (DFB) fiber lasers. Our results show that an asymmetrically chiped DFB fiber laser can undergo sustained self-pulsations at frequencies > 5 GHz. There pulsations result from the beating between two asymmetric longitudinal modes with different frequencies but similar gains. The population distribution remains essentially frozen during these oscillations. For fiber gratings, an asymmetric pulsations. Uniform or symmetrically chirped DFB lasers do not exhibit this instability.