Comparison of silica-based materials and fibers in side- and end-pumped fiber lasers

We have developed a production process for rare earth doped bulk silica to fulfill the demand of such material for fiber laser applications. In contrast to the standard techniques such as a combination of MCVD (modified chemical vapor deposition) and solution doping, our novel technology is based on a granulate process that enables novel ultra large mode area fiber designs (XLMA) with active core diameters above 100 μm as well as larger batch sizes. Several Yb-doped fibers with two different fiber designs were manufactured and successfully tested in both side- and end-pumped fiber laser setups. Both fiber designs have been compared to similar MCVD fibers. The influence of the material composition on the photodarkening properties has been investigated.