Yb3+-activated optical fibers with a core fabricated by sintering powders with vibration mixing of the melt

Using sintering of powders in combination with vibration mixing of the melt, glasses for cores of preforms of optical fibers of the composition SiO2-Al2O3-P2O5-Yb2O3 with a rather high (up to 0.5 at. %) ytterbium content were fabricated. Lasing on ytterbium ions was obtained in light guides with a core of these glasses. To increase the lasing efficiency, further optimization of the process parameters is required to reduce optical losses. It is shown that one of the causes of optical losses is the inhomogeneity of the glass microstructure at the nanoscale level and the formation of nanocrystalline inclusions, which are SiO2, YbP3O9, and YbPO4.