Er3+-doped boro-tellurite glass for optical amplification in the 1530-1580 nm

The paper investigates the influence of boric oxide (B(2)O(3)), which has a phonon energy of 1500 cm(-1), on enhancement in the population of the (4)I(13/2) level via the increased multiphonon relaxation in the Er-ion doped tellurite fibers. The paper discusses the structural compatibility of TeO(4) structures with BO(4) structural units and, therefore, the limitation on the solubility limits of boric oxide in the glass. In the present investigation the optimal composition demonstrates the minimum devitrification tendency in the glassy state that has one of the largest multiphonon relaxation rates. A comparison of lifetimes of (4)I(11/2) level is also made for other tellurite and boro-tellurite compositions. The experimental data show that the transition rate at (4)I(11/2)->(4)I(13/2) dramatically increased by incorporating 15 mol % B(2)O(3) without sacrificing the spectroscopic properties of glass. The lifetime at (4)I(11/2) transition level decreased from 213 to 54 mu s when B(2)O(3) is introduced into tellurite glass. We also report the calculated Judd-Ofelt parameters and the radiative transition rates, which increased by incorporating B(2)O(3) in the tellurite glass. Gain measurements in single-mode boro-tellurite fibers show an increase in peak internal gain from 10 to 13 dB and also, the overall gain spectrum broaden across the L band (1565-1605 nm). (c) 2008 American Institute of Physics.