Inhomogeneous and homogeneous linewidths in Er3+-doped chalcogenide glasses

The erbium I-4(13/2)-I-4(15/2) transition around 1.5 mum is of prim interest for telecommunications and depends on the erbium ions surrounding. In glasses, the broadening of a transition comes from two contributions: inhomogeneous (due to the disorder) and homogeneous (due to the electron phonon interaction) broadening. Resonant Fluorescence Line Narrowing (RFLN) is a useful tool to separate this two parameters. We will show in this paper that the I-4(13/2)-I-4(15/2) transition in chalcogenide glass (GeGaSSb) presents a strong homogeneous character and a smaller inhomogeneous contribution compared to aluminosilicate and fluoride glasses. Consequences on gain saturation will also be discussed. (C) 2003 Elsevier B.V. All rights reserved.