The power of laser diodes has increased in a spectacular fashion during recent years. The focus of this brief report will be to consider some of the problems associated with using high power diodes to pump fiber lasers and to discuss some of the schemes that have been proposed to overcome these problems. This is of particular importance at the present time because of recent interest in what might be termed extremely high power output. Over 100 W CW have already been obtained from a single Yb double clad fiber1, and elsewhere research is in progress to scale this up several orders of magnitude. At the present time, there are several sources of single mode fiber out put at 10-20 W, and one source is offering a single mode fiber laser of 100 W (IPG Polus)14. The Department of Defense has recently requested the submission of proposals for work that would lead to fiber lasers from 1 kW to 100 kW. This latter will clearly be concerned with the combination of multiple fiber lasers, and the aspect of coherent combination will not be considered in this presentation. It will be clear, however, that there is a need for design of fiber lasers that can efficiently utilize such very high diode pumping power.
Theodore F. Morse,
"Optically pumped high-power fiber lasers", Proc. SPIE 4648, Test and Measurement Applications of Optoelectronic Devices, (16 April 2002); doi: 10.1117/12.462646; https://doi.org/10.1117/12.462646