VUV and UV Florescence and Absorption Studies of Tb3+and Tm3+Trivalent Ions in LiYF4Single Crystal Hosts

The laser induced fluorescence spectra of LiYF4:Tb3+ (YLF:Tb) and LiYF4:Tm3+ (YLF:Tm) single crystals, pumped by an F2 pulsed discharge molecular laser at 157 nm, were obtained in the vacuum ultraviolet (VUV) and ultraviolet (UV) regions of the spectrum, at room temperature. A number of new fluorescence peaks were observed for the first time. They were assigned to the dipole allowed transitions 4f75d → 4f8 and 4f115d → 4f12 of Tb3+ and Tm3+ ions respectively. The absorption spectra of the same crystal samples in the VUV and UV regions were taken as well. The edge (onset) and the energy of the states with 4fN − 15d configuration were determined.