Application of high power diode lasers = Anwendungen von Hochleistungslaserdioden

During the last few years the development and fabrication technology of high power laser diodes (HPLD's) has led to major improvements concerning he available output power, the lifetime and especially the price of the devices. The initial motivation for developing HPLD's was focused on the pumping of solid state lasers in order to replace flashlamps or arc lamps to increase efficiency, beam quality, lifetime and reliability. But apart from this "indirect" application there is a vast potential in direct applications of the HPLD's in the field of material processing. This paper summarises activities of the Fraunhofer Institutes in Aachen and the Fraunhofer Resource Center in Ann Arbor concerning high power laser diode stacks and their direct industrial applications. At the moment a maximum diode beam intensity of 2 x 10(exp4) W/sqm is available with an output power of 300-400 W. By further improvements of the lens fabrication and alignment technology a beam intensity of 10(exp5) W/sqm wi ll be achieved in the near future /1/2/3/.