CHAOTIC BEHAVIOR IN ERBIUM-DOPED FIBER-RING LASERS

In this paper we report studies on the dynamical behaviors of erbium-d oped fiber lasers with one polarized mode. The chaotic behaviors, as w ell as the coexistent scenario of the period doubling and the intermit tently chaotic routes to chaos, are observed experimentally in this fi ber laser with pump modulation. Optical bistability and a simple bifur cation are also observed in different modulation frequencies. A simple theoretical model has been developed to obtain almost all the dynamic al behaviors. Another method to gain chaos in an erbium-doped fiber-ri ng laser system is a coupled-ring system. Theoretical study shows that chaos occurs in this dual-ring system. Again a bifurcation scenario i s found in the marginal region from self-pulsation to chaos. Interesti ngly enough, a duplicated ring can produce synchronized chaos. (C) 199 8 Optical Society of America.