Innovation and invention with high brightness lasers
It is nowadays common practice to use the term "high brightness" to specify any type of solid state disc or fibre laser source regardless whether they are working as single or multi mode systems. This view may be owed to the fact that these laser beam sources are considered as a new class of material processing tools which possess some features that differ from typical characteristics of conventional CO2 or Nd:YAG laser beam sources. It is also fair to say that the appearance of fibre and disc lasers in the multi-kW power range has stimulated a lot of experimental and theoretical work that generally gave new insights into the characteristics of laser materials processing. The availability of solid-state fibre and disc laser systems at multi-kW power levels has and still is having a major impact on the global laser community. Experimental and theoretical investigations continue to provide new insights into the characteristics of the different kinds of laser materials processing such as cutting and welding. The advantages and benefits of these lasers as well as challenges to realising their potential benefits have been highlighted. Besides quantitative enhancements in the performance of several existing applications, the high brightness of single-mode fibre lasers in particular have given rise to completely new and innovative processes. We expect that the continuation of investigations on the potential of high-brightness laser beam sources will continue to stimulating further inventions in the field of laser material processing.