High power and high luminance blue laser module using GaN-based laser diodes

Blue lasers are promising light source candidates for laser metal processing such as copper welding and heating, because copper has a high optical absorption coefficient in the blue spectral region. We have jointly developed 250 W blue Laser Diode (LD) modules including multiple LD chips with Furukawa Electric Co., Ltd. Their hybrid laser system consisting of an infrared fiber laser and the blue LD modules has already been commercialized. In this study, we report on the development progress for higher optical output power of the blue LD module used in the hybrid laser system. Specifically, we have achieved the output power for the LD module over 500 W from the fiber with a 110µm core diameter by increasing the output power of the constituent blue LD chip from 13 W to 16 W and the number of the installed LDs from 24 pcs to 36 pcs. The luminance is more than 5 MW/cm2 and the Beam Point Parameter (BPP) is almost 9 mm-mrad.