Fluorescence line narrowing in erbium-doped silica fibers

Abstract

The properties of erbium-doped silica fiber amplifier are significantly modified by the addition of only few percent of aluminum. For example, at room temperature, the 1.5 μm emission line width is multiplied by a factor two. In order to improve our knowledge on rare-earth transition broadening mechanism, primarily in fibers, nonresonant fluorescence line narrowing measurements were performed on erbium-doped silica fibers codoped with either aluminum or germanium, at low temperatures. An important variation in site distribution and Stark splitting was found depending on the matrix.