Spectroscopic signature of phosphate crystallization in Erbium-doped optical fibre preforms

In rare-earth-doped silica optical fibres, the homogeneous distribution of amplifying ions and part of their spectroscopic properties are usually improved by adding selected elements, such as phosphorus or aluminum, as structural modifier. In erbium ion (Er3+) doped fibres, phosphorus preferentially coordinates to Er3+ ions to form regular cages around it. However, the crystalline structures described in literature never gave particular spectroscopic signature. In this article, we report emission and excitation spectra of Er3+ in a transparent phosphorus-doped silica fibre preform. The observed line features observed at room and low temperature are attributed to ErPO4 crystallites

Spectral Hole-Burning of Nd3+\mathsf{Nd^{3+}} Doped Germanosilicate Fiber

We report the observation of spectral hole-burning in the $^{4}$I$_{9/2}$ $\rightarrow$ $^{4}$F$_{3/2}$ transition of Nd$^{3+}$ in a germanosilicate fiber. The temperature dependence of holes was measured in the range of 1.3-3 K and a power law of $T^{1.2+/-0.1}$ was found

U3+ doped fluoride glass emission at 2.5 µm

Fluorescence dynamics of trivalent uranium in ZBLAN or BATY glasses and ZBLAN fiber has been investigated at various temperatures. A carefull fluorescence analysis of all these systems allows to identify some of the crystal field components of the ground level J=9/2. Fluorescence decays of the 2.5µm emission have been recorded using an infrared nanosecond pulsed laser indicating an average lifetime of hundred of milliseconds at low concentration. The non exponential behavior of the decay increases with concentration