Excited states Tm spectroscopy in ZBLAN glass for S-band amplifier

We report on excited state spectroscopy measurements of Tm doped ZBLAN glass designed for fiber amplifier in the 1.48 μm wavelength range. Low temperature absorption, emission and Excited State Excitation measurements are reported to clearly identify the transitions involved in the different pump mechanisms of this Thulium Doped Fluoride fiber Amplifier. Room and low temperature Excited State Absorption spectra were recorded and quantitative determination of absorption cross sections has been obtained which allows to further proceed to a modeling of this amplifier.