n -type delta doped strained quantum well lasers for improved modulation bandwidth

Improved dynamic properties of strained single quantum well (QW) lasers were obtained by the incorporation of an n-type δ doping at close proximity to the strained QW active layer. The resultant modulation bandwidth was almost doubled, from 3.5 GHz to more than 6.2 GHz. The increased modulation bandwidth is attributed to an improved carrier injection resulting from the enhancement of the carrier transit time into the QW, as well as a decrease in the significance of the adverse contribution of carrier transport effects.