Influence of fluorine codoping on optical losses in Ge- and P-doped fibers

摘要

The influence of the fluorine-containing precursor type in the MCVD process on the size of soot particles is investigated by the method of laser ultramicroscopy. The results of these measurements have shown that Freon-113 decreases the content of large soot particles, while SiF_4 does not. These results suggest an explanation of the optical loss reduction in highly GeO_2-or P_2O_5-doped single-mode fibers due to co-doping of the fiber core with fluorine.