Influence of 4f absorption transitions of Dy3+ on the emission spectra of Tm3+-doped tellurite glasses

We have demonstrated that a fluorescence emission centered at similar to 81 0 nm responsible for Tm3+ :H-3(4) -> H-3(6) transition is effectively captu red via re-absorption by an absorption transition corresponding to Dy3+:H-6 (15/2) -> F-6(7/2) in tellurite glasses. It is known that Tm3+-doped fiber amplifiers operating at the 1450 nm band suffer from amplified spontaneous emission (ASE) at around 810 nm. Therefore, our experimental results imply that a Dy3+-doped layer introduced in the vicinity of the Tm3+-doped layer in an optical fiber, as a representative example, can efficiently absorb th e similar to 810 nm emission from thulium and consequently reduce the ASE p ower. (C) 2000 Elsevier Science B.V. All rights reserved.