Electronics Letters
Ground-state and excited-state absorption in rare-earth doped optical fibres
Michel MONERIE, Thierry Georges, P.L. François, J.Y. Allain, Didier Neveux
Abstract
We present a modelling of absorption in rare-earth doped optical fibres. The transmission through the fibre is derived from ground-state absorption (GSA) and excited-state absorption (ESA) parameters. Fitting to experimental data obtained with thulium at 676.4 nm (GSA only) and 647.1 nm (GSA + ESA) yields experimental values for the absorption parameters. At 647.1 nm, ESA gives rise to transmission decreasing with power, which modifies the usual behaviour of absorption saturation.