Orange and IR to violet up-conversion processes in Nd:ZBLAN glasses

In this work we investigate, compare and discuss UV and violet emission behaviour under pulsed, multi-photon orange and infra-red excitation in Nd3+ doped ZBLAN samples of different concentrations ranging from 0.3 to 5 mol.%. Supported by the obtained spectroscopic results, orange and IR excitation schemes were proposed and verified by time dependent rate equation model, which has been employed to confirm the nature of observed processes. Proposed model returns fitting results which qualitatively reflect the experimentally obtained fluorescence decays.