VUV AND UV FLUORESCENCE AND ABSORPTION STUDIES OF TB3-CRYSTAL HOSTS( AND TM3+ TRIVALENT IONS IN LIYF4 SINGLE)

The laser induced fluorescence spectra of LiYF4:Tb3+ (YLF:Tb) and LiYF 4:Tm3+ (YLF:Tm) single crystals, pumped by an F2 pulsed discharge mole cular laser at 157 nm, were obtained in the vacuum ultraviolet (VUV) a nd ultraviolet (UV) regions of the spectrum, at room temperature. A nu mber of new fluorescence peaks were observed for the first time. They were assigned to the dipole allowed transitions 4f(7)5d-->4f8 and 4f(1 1)5d-->4f12 of Tb3+ and Tm3+ ions respectively. The absorption spectra of the same crystal samples in the VUV and UV regions were taken as w ell. The edge (onset) and the energy of the states with 4f(N)-(1)5d co nfiguration were determined.