Judd-Ofelt parameters Ω//t with t=2,4,5 for the rare-earth ions Pr^3+, Nd^3+, Sm^3+, Tb^3+, Dy^3+, Ho^3+, Er^3+, and Tm^3+ in alkali and/or alkaline-earth silicate, borate, and phosphate glasses have been determined. The variations of Ω//t with the number of 4f electrons of the rare-earth ions are demonstrated, and factors affecting the Judd-Ofelt parameter Ω//6 are discussed. The intensity parameter Ω//6 depends on the ionic packing ratio of the glass host by changing modifier type in silicate and borate glasses, and it is independent of that in a series of borate glasses, and it is independent of that in a series of borate glasses as a function of modifier content and phosphate glasses. The peak wavenumbers of the transitions whose intensities are determined mainly by the Ω//6＜‖U(6)‖＞^2 term—where ＜‖U(6)‖＞ is one of the reduced matrix elements—shift systematically with the values of Ω//6 for all the rare-earth ions.
Takebe, Hiromichi. Nageno, Yoshikazu.