15-W Fiber-Coupled Quantum-Dot Pump Module

We have developed 920-nm pump modules for Yb-doped fiber amplifiers. The pump laser utilizes a single layer of In(AlGa)As/GaAs quantum-dot material as active region. Stable operation without thermoelectric cooling, output powers of up to 40 W, and wall-plug efficiencies of more than 50% have been achieved on processed broad-area laser bars. The packaged module reaches 15 W when coupled to a 200-mu m fiber.