Frequency upconversion in Pr3+-Li2O-TeO2 binary glass by decay curve analysis.

Using the decay curve analysis frequency upconversion under continuous wave NIR laser radiation ( approximately 890 nm) following the non-resonant excitation at higher energies than 1G4 level has been reported. The decay curve of the antistokes emission (3P0-->3H4) shows similar behavior as that of the stokes emission (3P0-->3H4) and does not show any rise time attributing to the excited state antistokes absorption assisted by phonon emission. The covalency, bonding parameters and nephalauxetic effect for the present system has also been determined.