Improvement of the Tm3+:3H4 level lifetime in silica optical fibres by lowering the local phonon energy

Basile Faure (1) , Wilfried Blanc (1) , Bernard Dussardier (1) , Gérard Monnom (1)

1 LPMC - Laboratoire de physique de la matière condensée

The role of some glass network modifiers on the quantum efficiency of the near-infrared fluorescence from the 3H4 level of Tm3+ ion in silica-based doped fibres is studied. Modifications of the core composition affect the spectroscopic properties of Tm3+ ion. Adding 17.4 mol% of AlO3/2 to the core glass caused an increase of the 3H4 level lifetime up to 50 µs, 3.6 times higher than in pure silica glass. The quantum efficiency was increased from 2% to approximately 8%. On the opposite, 8 mol% of PO5/2 in the core glass made the lifetime decrease downto 9 µs. These changes of Tm3+ optical properties are assigned to the change of the local phonon energy to which they are submitted by modifiers located in the vicinity of the doping sites. Some qualitative predictions of the maximum achievable quantum efficiency are possible using a simple microscopic model to calculate the non-radiative de-excitation rates.

Mots clés: Optical fibers; Luminescence; Optical spectroscopy; Time resolved measurements; Alumino-silicates; Silica; Rare-earths in glasses

Domaines: Optique [physics.optics]

Basile Faure, Wilfried Blanc, Bernard Dussardier, Gérard Monnom. Improvement of the Tm3+:3H4 level lifetime in silica optical fibres by lowering the local phonon energy. Journal of Non-Crystalline Solids, 2007, 353, pp.2767-2773. ⟨10.1016/j.jnoncrysol.2007.05.025⟩. ⟨hal-00460043⟩