Influence of process parameters on the incorporation of phosphorus into silica soot material during MCVD process

The incorporation of phosphorus into silica soot material strongly changes during the multistep preparation process of the MCVD technology in combination with solution doping for Al and rare earths. We report on the influence of various process parameters on the phosphorus concentration, the bond types of phosphorus atoms and the relative density of the soot material. By optimization of the process the phosphorus concentration of the presintered soot could be increased by around 10% in comparison to the conventional treatment. The understanding of the interdependencies allows an improvement of the preparation process of phosphorus co-doped RE doped silica laser fibers with MCVD technology.