Preparation and Performance of Cr3+/Tm3+/Ho3+ Co-Doped Fluorophosphate Glasses

Fluorophosphate glasses with various Al(PO3)3 contents were prepared，and their structure,thermal properties and spectral properties were studied.The emission properties at around 2.0μm of Cr3+/Tm3+/Ho3+ co-doped fluorophosphate glasses with different mole fractions of Tm3+ and Ho3+were studied. The spectral strength parameters Ωt(t=2,4,6) of those glasses have been calculated. Meanwhile,the spectral parameters, including the oscillator strength,spontaneous emission probability and branching ratios of Ho3+, have been calculated. The results show that the 2.0μm emission intensity gradually grows higher with the increase of the mole fraction of Tm3+. The Tm3+→(3F4) →Ho3+(5I7) energy transfer in (Tm3+/Ho3+) co-doped fluorophosphate glasses is very efficient, and it is dependent on the doping concentration.