High Power Laser Diodes

摘要

In the recent past tremendous progress has been made in the area of high power laser diodes. We will review the state of the art in the field of 9xxnm high power laser diodes and will discuss new requirements as well as physical and engineering limits. High power laser diodes have been far too weak to be used directly for industrial applications, such as marking and material processing (brazing, annealing, welding and cutting of steel). Therefore, high power diode lasers were (and still are) mostly used only indirectly to power up the lasing crystals of high power DPSS lasers, mostly as 808nm bars for YAG rods, and, more recently, 940nm bars for YAG disks. The 808nm application makes poor use of the diode capability, the 940nm application is already much better matched to the laser diode. However, but both systems still rely heavily on open space opto-mechanics (a hybrid assembly of open diodes, free space lenses and mirrors) and on micro channel cooling for heat removal, both with its associated reliability challenges.