Spectroscopic characterization ofEr3+-dopedTl3PbBr5for midinfrared laser applications

This paper presents the optical and spectroscopic properties of a low-phonon-energy, moisture-resistant, and nonlinear ${\mathrm{Er}}^{3+}:{\mathrm{Tl}}_{3}\mathrm{Pb}{\mathrm{Br}}_{5}$ single crystal. Though only weakly doped with ${\mathrm{Er}}^{3+}$ ions, centimeter-sized and good quality single crystals could be grown and analyzed. Excitation and emission spectra recorded at low temperature and crystal-field calculations agree with the existence of only one dominant ${\mathrm{Er}}^{3+}$ substitutional site. Anti-Stokes emission and excitation spectra as well as fluorescence decays and time-resolved emission and excited-state excitation spectra were recorded and analyzed to determine the different ways of populating the ${\mathrm{Er}}^{3+}$ excited levels and to provide all the necessary elements for an estimate of the laser potential of the considered material under diode laser pumping around $800\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$.