Upconversion losses in Nd-doped fluoroarsenate glasses

In this work we report the infrared to visible upconversion processes in Nd-doped fluoroarsenate glasses that produce green, orange, and red emissions together with the dynamics of the 4F3/2 state. The visible emissions can be attributed to transitions from the 4G7/2 excited state populated by energy transfer upconversion (ETU). It was found that ETU processes involving two Nd3+ ions in the 4F3/2 state reduce the energy storage capacity through the reduction of the fluorescence lifetimes of the 4F3/2 state. From the analysis of the temporal evolution of the infrared emission from the 4F3/2 state we have estimated the macroscopic ETU parameter for the samples studied.