The effects of crystal-fields on the optical properties of Pr:ZBLAN glass

Absorption and emission spectra of Pr3+-doped ZBLAN glass at room temperature were estimated from even- and odd-parity components of crystal-field parameters based on crystal-field theory and Judd–Ofelt theory. On the basis of point-charge approximation, the crystal-field parameters were obtained from structural models prepared by using molecular dynamics (MD) simulation. The calculated oscillator strengths for the 1D2 and 3PJ states were insufficient for the reproduction of the observed oscillator strengths for those states. These spectra were also estimated on the basis of the modified Judd–Ofelt theory, in which the variation of the energy difference between the 4f2 and the excited 4f15d1 or 4f15g1 configurations were taken into account. It was found that the oscillator strengths increased and the values were comparable to the observed ones. The effect of the even-parity components of the crystal-field on the splitting of the energy levels and the rate of the forced electric-dipole transition were investigated. The contribution of the crystal-field and the energy variation of the 4f2 configurations on the Judd–Ofelt intensity parameters was evaluated.