Excited state absorption spectroscopy of Nd3+ activated fluoroaluminate glass - experiment and simulation

We present excited state absorption (ESA) spectroscopy of Nd3+-activated fluoroaluminate glass. The ESA spectra were measured in the range from 550 to 1800 nm by the continuous-wave pump-probe technique. Judd-Ofelt (JO) formalism was employed to interpret the results. The obtained intensity parameters and linewidths were used to simulate the ESA spectra, which were successfully compared with the experimental data. The calculated ESA spectra were also used to precisely assign previously observed upconverted emissions and to predict additional ones, which were experimentally verified. The presented upconverted luminescence spectrum contains several anti-Stokes emission lines at 355 nm, 381 nm, 412 nm and 448 nm, and is in good agreement with the calculations.