High-performance (high optical output power, high efficiency), GaAs-based Quantum Dots (QD) 1.3 μ m edge emitting laser (EEL) results are presented. The active region is based on multiple stacks of InAs/GaInAs/GaAs QD. The whole structure has been grown in a multiwafer production MBE system (using 5 x 3" substrate holders). Threshold current density of 190A/cm(2) and high differential quantum efficiency of 70% were obtained at room temperature. These excellent values in addition to good I-V characteristics (1.1 V turn on voltage and series resistance as low as 2 x 10(-4) &UOmega; cm(2)) led to record continuous wave (CW) output power of 4.2 W for broad area devices (100 μ m wide, 1600 μ m long). © 2005 Elsevier B.V. All rights reserved.