ON THE VUV AND UV 4F(7)(S-8)5D-]4F(8) INTERCONFIGURATIONAL TRANSITIONS OF TB3-CRYSTAL HOSTS( IONS IN LILUF4 SINGLE)

The laser induced fluorescence spectrum of Tb3+ ions in LiLuF4 single crystals, pumped by a fluorine pulsed discharge molecular laser at 157 .6 nm, was obtained in the vacuum ultraviolet (VUV) and ultraviolet (U V) regions of the spectrum. The 4f(7)5d --> 4f(8) dipole allowed trans itions originate from the Stark components and the edge of the levels of the 4f(7)(S-8)5d electronic configuration. The LIF spectra were int erpreted on the basis of phonon trapping and phonon reabsorption withi n the levels of the 4f(7)5d electronic configuration. The absorption s pectrum of the crystal samples in the VUV was obtained as well. We obs erved eight transitions between the ground level 4f(8)(F-7(6)) and the Stark components of the levels of the 4f(7)(S-8)5d electronic configu ration and five transitions between the ground level 4f(8)(F-7(6)) and the Stark components of the levels of the 4f(7)(S-8)5d electronic con figuration. The edge of the levels of the 4f(7)5d electronic configura tion was found to be at 45.2 X 10(3) +/- 0.2 X 10(3) cm(-1) and the ba nd gap of the crystal host was 77.6 X 10(3) +/- 0.3 X 10(3) cm(-1) wid e. (C) 1998 Elsevier Science B.V. All rights reserved.