We present results on the realization of a multicolour
microspherical glass light source fabricated from the erbium doped fluoride
glass ZBLALiP. Whispering gallery mode lasing and upconversion processes
give rise to laser and fluorescent emissions at multiple wavelengths from
the ultraviolet to the infrared. Thirteen discrete emissions ranging from
320 to 849 nm have been observed in the upconversion spectrum. A Judd-Ofelt
analysis was performed to calculate the radiative properties of
Er3+:ZBLALiP microspheres, including the radiative transition
probabilities, the electric dipole strengths, the branching ratios and the
radiative lifetimes of the transitions involved. We have also identified the
primary processes responsible for the generation of the observed wavelengths
and have shown that this material has an improved range of emissions over
other erbium doped fluoride glasses.