Transform-limited 1.4 ps optical pulses from a monolithic colliding-pulse mode-locked quantum well laser

We report the generation of short optical pulses from novel monolithic colliding-pulse mode-locked quantum well lasers. Transform-limited pulses with durations of 1.4 ps at a repetition rate of 32.6 GHz have been achieved, with nearly 100% intensity modulation depth and a peak optical power of 10 mW. This is the shortest transform-limited pulse directly generated from monolithic mode-locked lasers (time-bandwidth product =0.3).