The influence of Si'O IND. 2' content on spectroscopic properties and laser emission efficiency of 'Yb POT. 3+'-'Er POT. 3+' co-doped calcium aluminosilicate glasses - Borrero-González, L. J; Terra, I. A. A.; Nunes, Luiz Antônio de Oliveira; Farias, A. M.; Barboza, M. J.; Rohling, J. H.; Medina, A. N.; Baesso, Mauro Luciano (Applied Physics B, 2012)