Power-scaling of blue diode pumped solid-state lasers for the visible wavelength range

Blue-emitting GaN-laserdiodes are now commercially available with output powers reaching the Watt-level. The emission wavelength of these devices around 445nm matches nicely the absorption of the Pr³⁺-ion. Several recent publications have reported output power levels from GaN-diode pumped Pr-lasers in the order of 30-50mW, which is still too low for the compact projectors mentioned above. In this paper we report the results of our work towards higher output power from these devices. Thus our results show that, we have increased the output power and the power conversion efficiency from electrical to green output power of a blue diode pumped solid-state laser to 120mW and 5% respectively.