Abstract
Low-cost, efficient, and compact high-power laser diodes (LDs) will make desktop laser manufacturing (rapid prototyping, sintering, drilling, marking, etc.) a reality soon. Laser processing of materials requires not only high average power, from tens of watts to kilowatts, but also high incident beam intensity or power density, from 103 to 108 W/cm2. Current commercial high-power LDs do emit 108 W/cm2; however, they are microscopic in size, and an individual diode emits ~ 1 W (cw) in a highly divergent (~30 x 10 deg) multimode structure. Gathering high power from a large number of such microscopic incoherent diodes into a small spot of high intensity requires micro-optic component and complex system design. Several difterent design approaches for high-intensity laser-diode systems are presented. Some of these are commercial, others will be soon, and still others will need technological developments. Possible applications and some preliminary results of direct diode-laser sintering and transformation hardening of stainless-steel ribbons are also presented.
