Abstract
Passively mode-locked distributed-Bragg-reflector (DBR) lasers with an intracavity saturableabsorber were monolithically fabricated. A transform-limited pulse train with a durationof 3.5 ps has was successfully generated at a high repetition rate over 40 GHz. While maintainingthe transform-limited conditions, a wide lasing-wavelength tuning of 4 nm was achieved byinjecting a tuning current into the DBR section. When an active region current was increasedup to a few times the threshold, harmonic passive mode-locking was also observed. Terahertzratepulse generation has been successfully achieved, to our knowledge for the first time, froma one-chip optoelectric device. The DBR section was found to play significant role in generatingstable pulses without substructure, by providing frequency filtering that selects longitudinalmodes.
