8 μm luminescence from a Tb GaGeSbSe fiber.

In this Letter, we report for the first time, to the best of our knowledge, on an emission at 8 μm from Tb-doped GaGeSbSe chalcogenide fibers with doping levels at 1000 ppm and 500 ppm. These fibers were drawn following conventional melt-quenching methods and pumped at 2.05 μm using a Tm: YAG laser. The spectroscopic properties of the emitting F7 manifold are investigated to rule out any parasitic signal mimicking the real Tb 8 μm emission. Time-resolved spectroscopic experiments are presented to build a comprehensive study of this 8 μm fluorescence recorded with a clear signal-to-noise ratio.