Optical properties and concentration dependence of the luminescence of Pr3+ion in fluoroindate glass

Abstract

AbstractOptical absorption and emission spectra are presented for Pr3+and Pr3++ Cr3+ions in fluoroindate glass. Also, X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements are carried out in order to characterize investigated materials. The measured oscillator strengths and radiative rates for several transitions of the Pr3+ion are compared with calculated values. Radiative transition rates for the excited states are determined by using the Judd–Ofelt theory. Energy transfer effects account for the non‐radiative transitions. Although the Judd–Ofelt analysis does not yield the same excellent consistency for Pr3+as for Nd3+and Er3+, the experimental observations are consistent with Judd–Ofelt calculations. The linear concentration quenching and exponential decay times of the1D2level are explained assuming cross‐relaxation and energy transfer between the Pr3+ions. Energy level diagrams of Cr3+and Pr3+reveal that the1G4level of Pr3+lies close in energy to the4T2fluorescent level of Cr3+, and hence will expect a portion of excitation energy from Cr3+. Unfortunately, the mismatch in energy of this Pr3+level with the4T2level of Cr3+(∼3000 cm–1) cannot be compensated for by the phonons of the host, having an energy of about 500 cm–1.