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2005
Conference Paper
Titel
Status and trends in the development of high-power diode lasers and their applications
Titel Supplements
Abstract
Abstract
In the past few years diode lasers have evolved into tools for industrial manufacturing for instance for soldering, plastics welding, transformation hardening and heat-conduction welding. The high efficiency, compactness and in particular the high modularity makes them superior to conventional CO2- or Nd:YAG-lasers for the applications mentioned above. In the low-power regime fiber-coupled diode lasers are dominating. In these systems a variety of different beam transformation techniques are common for the forming of the line-shaped beam of a diode-laser bar into a spot which can be efficiently coupled into an optical fiber of circular cross section. At higher output powers diode laser stacks are commonly used, supplied with micro-optical cylinder lenses for collimation and shaping of the individual beams. A major limitation of presently available high-power diode lasers is the limited beam quality, which still is more than an order of magnitude lower than that of conventional lasers. A broad spectrum of activities is necessary and currently performed in order to increase the brightness: - increase of power and beam quality of the diode laser bar, - increased quality of micro-optics and packaging, - wavelength and polarization coupling. By means of these techniques output-power as well as beam quality have already been considerably increased in the past few years. Further improvements will be achieved in the future. With the new diode lasers the range of applications in industrial manufacturing can be increased considerably. Diode lasers are currently used in more mature applications such as transformation hardening, soldering and plastics welding but due to the increased beam qualities are now able to weld and cut metals as well. The unique feature of modularity of diode lasers is used in applications such as simultaneous hardening, single shot welding and marking with individually addressable diode laser bars.