High-power diode lasers for direct applications

Diode-laser systems have a good chance to be used as light sources for dire ct applications. For this purpose a large number of relatively weak light b undles originating from individual oscillators have to be coupled to a sing le powerful beam. The coupling may be done in a completely incoherent way i n cases where only a moderate beam quality is appropriate or with increasin g degrees of coherence corresponding to applications where high demands on the quality are necessary. In this article all current methods of incoheren t as well as of coherent beam combining are described and judged with respe ct to their present and future potential.