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Line shape and lifetimes of Cr 3 + luminescence in silicate glasses

1991; American Physical Society; Volume: 44; Issue: 10 Linguagem: Inglês

10.1103/physrevb.44.4853

1095-3795

M. Yamaga⋆, B. Henderson, K.P. O’Donnell, Yachen Gao,

Quantum optics and atomic interactions

This paper describes experimental and theoretical studies of the distribution of crystal-field sites occupied by ${\mathrm{Cr}}^{3+}$ ions in silicate glasses. The effects of this site-to-site disorder on the optical band shape of $^{4}$${\mathit{T}}_{2}$${\ensuremath{\rightarrow}}^{4}$${\mathit{A}}_{2}$ and $^{2}$E${\ensuremath{\rightarrow}}^{4}$${\mathit{A}}_{2}$ transitions, luminescence decay time, and their temperature dependences are calculated and compared with experimental results. Since the distribution of the crystal-field splitting, 10Dq, includes sites having values of the energy separation E${(}^{4}$${\mathit{T}}_{2}$)-E${(}^{2}$E), which vary from positive, through zero to negative, it is necessary to take into account the effects of $^{4}$${\mathit{T}}_{2}$ to $^{2}$E tunneling induced by spin-orbit coupling and zero-point vibration. Good agreement is obtained between theory and experiment, giving confidence in the assumed distribution of crystal-field sites.