Spatial and spectral emission characteristics and efficiency of high-power diode laser (HPDL) based pump sources
enable and define the performance of the fundamental solid state laser concepts like disk, fiber and slab lasers.
HPDL are also established as a versatile tool for direct materials processing substituting other laser types like CO2 lasers
and lamp pumped solid state lasers and are starting to substitute even some of the diode pumped solid state lasers. Both,
pumping and direct applications will benefit from the further improvement of the brightness and control of the output
spectrum of HPDL.
While edge emitting diodes are already established, a new generation of vertical emitting diode lasers (VCSELs) made
significant progress and provides easy scalable output power in the kW range. Beneficial properties are simplified beam
shaping, flexible control of the temporal and spatial emission, compact design and low current operation. Other
characteristics like efficiency and brightness of VCSELs are still lagging behind the edge emitter performance.
Examples of direct applications like surface treatment, soldering, welding, additive manufacturing, cutting and their
requirements on the HPDL performance are presented. Furthermore, an overview on process requirements and available
as well as perspective performance of laser sources is derived.