NIR fluorescence and visible upconversion studies of Nd3+ ions in calcium fluoroborate glasses

This Letter reports on the preparation, optical absorption, NIR fluorescence and visible upconversion studies of neodymium doped calcium fluoroborate (CFB) glasses. The title glasses were prepared by melt quenching technique and the phonon energy of the host glass was estimated by the FTIR spectrum. Radiative parameters of various transitions/levels were calculated by applying Judd–Ofelt (J–O) theory. The concentration dependence of NIR emission and visible upconversion intensities from the 4F3/2 and 2D3/2 levels has been discussed. Decrease of experimental lifetime of 4F3/2 level with concentration has also been discussed by recording decay curves of the NIR emission.