Investigation of spectroscopic properties and thermal stability of Er3+/Yb3+-co-doped Bi2O3-B2O3-Ga2O3 glasses

A series of Er3+/Yb3+-co-doped 60Bi(2)O(3)-(40-x) B2O3 -xGa(2)O(3) (BBGA x = 0, 4, 8, 12, 16 mol%) glasses have been prepared. The absorption spectra, emission spectra, fluorescence lifetime of Er3+:I-4(13/2) level and thermal stability were measured and investigated. Three Judd-Ofelt intensity parameters Omega(t) (t = 2,4,6) (02 = (4.67-5.93) x 10(-20) cm(2), Omega(4) = (1.50-1.81) x 10(-20) cm(2), Omega(6) = (0.92-1.17) x 10(-20) cm(2)) of Er3+ ions were calculated by Judd-Ofelt theory. It is found that the Omega(6) first increases with the increase of Ga2O3 content from 0 to 8 mol% and then decreases, which is mainly affected by the number of non-bridging oxygen ions of the glass network. The high peak of stimulated emission cross-section (sigma(peak)(e) = 0.83 - 1.03 x 10(-20) cm(2)) of Er3+:I-4(15/2)-> I-4(15/2) trasnition were obtained according to McCumber theory and broad full width at half maximum (FWHM = 69-76 nm) of the I-4(13/2)-> I-4(15/2) transition of Er3+ ions were measured. The results indicate that these new BBGA glasses can be used as a candidate host material for potential broadband optical amplifiers. (C) 2008 Elsevier B.V. All rights reserved.