Recent advances in high power blue laser diodes

We present the improvements in power conversion efficiency of high power multi-mode blue laser diodes. The improved device architecture shows a peak wall plug efficiency of ∼ 44.2 % at room temperature. Furthermore, the device delivers an optical output power reaching 3.7 W at the peak efficiency. The signs of thermal roll-over at room temperature start appearing near 5 A of injection current for this particular device design. The device generates an optical output power of more than 7.5 W with overstressed current injection at room temperature. We have also evaluated the high temperature electro-optical performance. The roll-over point is shifted by approximately 1 A when the device is operating at 85°C. The optical output power reaches 4.8 W at thermal roll-over.