Femtosecond carrier dynamics and modelocking in monolithic CPM lasers

Femtosecond pump-probe measurements of the dynamics in both forward- and reverse-biased semiconductor optical waveguides are presented. Slow (nanosecond) as well as ultrafast (femtosecond) dynamics are observed in both kinds of structures. These measurements imply that the "slow saturable absorber" theory of modelocking in monolithic CPM devices is incomplete.