Concentration quenching of fluorescence from the (3P0+3P1) manifold in heavily-doped Pr3+: ZBAN glasses

Abstract Fluorescence waveforms from the ( 3 P 0 + 3 P 1 ) manifold in Pr 3+ doped ZBAN glass at wavelengths of 520, 635 and 695 nm were measured for Pr 3+ concentrations from 4 to 12 mol%. The waveforms were found to be non-exponential with decay rates rapidly increasing with Pr 3+ concentration and independent of whether the 3 P 0 or the 3 P 1 level was excited. The multipolar energy transfer model was used to analyse the waveforms and this showed that concentration quenching was due to cross-relaxation by dipole–dipole interaction. The critical concentration, at which the cross-relaxation rate equals the intrinsic decay rate, was found to be of 2.06 × 10 26 m −3 (1.20 mol%). There was no evidence of excitation diffusion for Pr 3+ concentrations of up to 12 mol%.