A novel technique to achieve strong colliding-pulse effect in CPM QW LD
We introduce in this paper a novel structure to achieve ultrashort optical pulses in colliding-pulse mode-locking (CPM) quantum well laser diodes. Two modulation segments have been introduced symmetrically around the center saturable absorber and the 5-segment CPM-LD is thus fabricated. By changing the injected current on the modulation segments separately, the optical FWHM has been been shortened from 1.6 ps, giving a narrowest pulse width without modulation segments of up to 0.96 ps.