Fluorescence and radiative properties of Nd3+ ions doped zinc bismuth silicate glasses

Glasses having composition 20ZnO center dot xSiO(2)center dot(79.5-x)Bi2O3 center dot 0.5Nd(2)O(3) with x varying from 10 to 50 mol% have been synthesized. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. Optical absorption and fluorescence spectra were measured at ambient temperature. This paper reports on different physical and absorption spectral properties of Nd3+ doped zinc bismuth silicate glasses with varying content of Bi2O3 to understand its influences on hypersensitive band intensities. From the recorded absorption spectra, Judd-Ofelt intensity parameters Omega(lambda) = (lambda = 2, 4, 6) have been evaluated with their quality factors and are used to compute the radiative properties of Nd3+ glasses. The calculated Judd-Ofelt parameters are found to decreasing with decrease in Bi2O3 content in the glass which may be due to the decrease in Nd-O bond covalency. From these intensity parameters various radiative properties like spontaneous emission probability (A(rad)), radiative life time (iota(r)), fluorescence branching ratio (beta(r)) and stimulated emission cross-section (sigma) for various emission bands have been calculated. The stimulated emission cross-section of fluorescence transition F-4(3/2) -> I-4(11/2) have high values and varies from 15.19 x 10(-20) cm(2) to 5.73 x 10(-20) cm(2) with Bi2O3 content in the host glass. The results point out this glass system as good candidate to be used in the development of photonics devices operating in the near infrared spectral range. Further, the FTIR results reveal that the glasses have BiO6, SiO4 and non-bridging oxygen as local structure. (C) 2013 Elsevier B. V. All rights reserved.