[MathML equation] emission performance in Ho(3+) doped fluorophosphate glasses sensitized with Er(3+) and Tm(3+) under 800 nm excitation

The spectroscopic properties and energy transfer mechanisms in Ho(3+) doped fluorophosphate glasses sensitized by Er(3+) and Tm(3+) at the 2 km region are investigated. The absorption spectra and fluorescence spectra of the Tm-Ho doubly-doped glass system and Er-Tm-Ho triply-doped glass system are measured. According to the absorption spectra, the Judd-Ofelt parameters and spontaneous transition probability are calculated and compared with those of other glass hosts. From the fluorescence spectra, the fluorescence intensity of Er-Tm-Ho glass system at 2.0 km is 0.95 and larger than that of the Tm-Ho glass system, which is 0.69. Meanwhile, the 2.0 km to 1.8 km and 2.0 km to 1.53 km peak intensity ratios in the Er-Tm-Ho glass system are 8.63 and 22.79, respectively, suggesting sufficient energy transfer between Er(3+), Tm(3+) and Ho(3+) ions. In addition, the pumping schemes and energy transfer mechanisms of Tm- Ho doubly-doped and Er-Tm-Ho triply-doped glasses are discussed. The study indicates that the Er-Tm-Ho triply-doped glass system is a significant sensitized way pumped at 800 nm in fluorophosphate glasses for 2 km applications.