Pump Laser Diode Module

Experimental and theoretical evidence indicate that charge localization through a quantum dot active region can significantly increase pump laser diode performance by reducing threshold current density and internal loss. Because of its charge localization and lower operating current density, quantum dot active material has demonstrated increased resistance to radiation-induced defects. sdPhotonics will use a novel quantum dot laser diode design to obtain low internal loss combined with a long cavity length of >2 cm to develop a proof-of-concept laboratory demonstration of a 980 nm high power quantum dot laser suitable for high power single mode fiber pumping. The Phase I will utilize a low loss waveguide design and fabrication presently under development for high power broad area stripe bars of quantum dot diodes, modified for narrow stripe operation and fiber pigtail pumping. High power fiber coupling will be achieved through waveguide broadening to obtain a narrow beam profile and a low alpha factor of the quantum dot active material. Designs will be developed for delivering > 5W CW into a fiber, based on measured beam and power characteristics. Laser diode fabrication will focus on high yield manufacturing and stress free mounting for increased reliability.