Quantum efficiency of Pr3+ doped transparent glass ceramics

Abstract

The quantum efficiency of the 1.3 μm transition in Pr3+ doped oxyfluoride transparent glass ceramics is measured using a self-calibrating fluorescence ratio technique. The measured value of 8%±1% is much higher than expected for Pr3+ in an oxide glass, and is consistent with the incorporation of the Pr3+ ions into the fluoride nanocrystals of the glass ceramic. Measured quantum efficiencies are compared with values calculated using the Judd–Ofelt theory, and it is found that the best agreement is obtained when fractional differences between calculated and measured oscillator strengths are minimized, rather than absolute differences. The Judd–Ofelt analysis is used along with a spectral analysis to show that excited-state absorption should not significantly reduce the gain around 1.3 μm in these materials. The fluorescence ratio technique used to measure the quantum efficiency also provides information about ion–ion interactions at higher concentrations. It is found that the addition of the monovalent dopant Ag+ reduces the tendency of the Pr3+ ions to cluster, allowing higher concentrations of Pr3+ without significant concentration quenching.

Optical intensities of Pr3+ ions in transparent oxyfluoride glass and glass–ceramic. Applications of the standard and modified Judd–Ofelt theories

“…These spectra confirm that the transparency of the glass-ceramic is quite similar to that found in the precursor glass since, apart from those bands associated to the Pr 3+ ions, both samples show the typical increase in the absorbance in the UV-A region. The bands correspond to intra-configurational 4f 2 -4f 2 elec- tronic transitions, starting from the 3 H 4 ground state to the different excited levels of the Pr 3+ ion, and all the transitions are assumed to be electric dipole in nature [13]. As can be seen, there are practically no differences in the energies of the transitions in the glass and the glass-ceramic, although for the latter the bands are sharper and some of them, such as 3 H 4 → 1 D 2 and 3 H 4 → 3 F 3 , clearly show structure, giving an experimental evidence that the Pr 3+ ions have been incorporated in the fluoride nanocrystals.…”

“…Tick et al [12] and Quimby et al [13] have analysed the optical properties of these oxyfluoride glass and glass-ceramic applying the Judd-Ofelt technique, but using only absorption oscillator strengths. Moreover, they have excluded the 3 H 4 → 3 P 2 transition and two different sets of Judd-Ofelt parameters have been found depending on the method of calculation.…”

Tm3+-activated transparent oxy-fluoride glass–ceramics: structural and spectroscopic properties

“…The motivation for this research is combining the mechanical and optical properties of the glass with a crystal-like environment for the rare-earth ions, where their higher cross-sections can be exploited in order to fabricate more compact devices [2][3][4]. Moreover the glass-ceramic materials can provide a low phonon energy host, this is the case for oxyfluoride glass-ceramic where the nucleated crystalline phase is fluoride.…”

Structural, absorption and fluorescence spectral analysis of Pr3+ ions doped zinc bismuth borate glasses

“…As a general conclusion,˝2 parameter increases with asymmetry of the local structure and with the degree of covalency of the lanthanideligand bonds, whereas˝6 parameter decreases with the tendency of covalency. In addition,˝4 parameter is believed to be related to the bulk properties of the samples [31].˝2 is higher for the present glasses in comparison to oxy-fluoride [31], tellufluoro-phosphate [32], fluorozirconate [33], mixed-halide [33] and ZBLAN glasses [34] except for ZBP 1 glass sample. This indicates that the asymmetry and covalency of Pr 3+ ions in the zinc bismuth borate glasses are stronger than those in the others glasses mentioned above.…”