Self-absorption and radiation trapping in -doped -based glassesM. Mattarelli, M. Montagna, L. Zampedri, A. Chiasera, M. Ferrari, G. C. Righini, L. M. Fortes, M. C. Gonçalves, L. F. Santos and R. M. AlmeidaEurophys. Lett., 71 3 (2005) 394-399DOI: https://doi.org/10.1209/epl/i2005-10092-4