Abstract: The first colliding pulse mode-locked operation of devices fabricated from broad gain spectrum multiple-width quantum well material is reported. Using multiple-width quantum wells in the active region of the InGaAs/InAlGaAs material system, 35% broader gain bandwidth has been obtained in comparison to the conventional identical width quantum well material. For the colliding pulse mode-locked operation, observation made from the optical spectra showed that the multiplewidth quantum well laser provided one extra optical mode with the pulse width narrowing by 7% in comparison to the identical width quantum well laser
