Laser spectroscopy and upconversion studies of Pr3+-doped halide modified sulfide glasses

The visible luminescence of Pr 3+ -doped halide modified sulfide glasses has been investigated for different halide modifiers and Pr 3+ concentrations by using steady-state and time-resolved laser spectroscopy. The measured luminescence lifetime of level 3 P 0 is nearly independent on Pr 3+ concentration up to 0.7 mol% whereas the fluorescence of the 1 D 2 level shows concentration quenching for Pr 3+ concentrations higher than 0.5 mol% even at low temperature. The IR-to-visible upconversion obtained under continuous wave infrared laser excitation has been investigated for all samples. The excitation wavelength and pumping power dependencies of the upconverted emission allow to point out two different upconversion mechanisms to populate the 3 P 0 and 1 D 2 levels.