Spectroscopy in the 1.4 and 1.8-?m wavelength regions of KPb2Cl5 single crystals doped with trivalent Thulium

A KPb2Cl5 crystal doped with trivalent Thulium ions has been grown using the Bridgman technique. We report the spectroscopic characterization of the Tm3+:KPb2Cl5 single crystal. Polarized absorption, continuous and dynamical fluorescence in the near infrared region are reported and discussed taking in account the possible defects that affect the crystals. The emission cross sections of the transition H43->F43 (1.4 micron) and F43->H63 (1.8 micron) are reported. The results suggest this crystal as a promising emitting material in the near-infrared region.