Photon-avalanche upconversion in 'Tm POT.3+'-doped fluoroindogallate glasses - Bell, Maria José Valenzuela; Sousa, Dione Fagundes de; Oliveira, S. L.; Lebullenger, Ronan; Hernandes, Antônio Carlos; Nunes, Luiz Antônio de Oliveira (Journal of Physics-Condensed Matter, 2002)