The use of n-type modulation doping to reduce the threshold current, the carrier lifetime, and the infernal loss in 1.3-mu m InGaAsP-InP strained multiquantum-well (MQW) lasers is experimentally demonstrated. The threshold current density, the carrier lifetime, and the internal loss were reduced by about 33% 36%, and 28%, respectively, as compared with an undoped MQW laser, Moreover, the turn-on delay time in the n-type modulation-doped MQW lasers with a low-leakage buried heterostructure was reduced by about 35%, These results confirm the suitability of this type of laser for use in the basic structure of a monolithic laser array used as a light source for high-density parallel optical interconnection.