Nonuniform carrier distribution in multiple quantum well laser diodes

Summary form only given. In general, increasing the number of wells reduces the threshold current density per well and increases the differential gain coefficient for QW laser diodes. However, there exists an optimum well number to maximize the differential gain, possibly due to the nonuniform carrier distribution. In this work, we demonstrate the evidence of nonuniform carrier distribution by measuring the lasing characteristics of the laser diodes fabricated on substrates with the designed MQWs. The layer structures of the substrates with four quantum wells for the study are schematically.