ON THE 4F(2)5D-]4F(3) INTERCONFIGURATIONAL TRANSITIONS OF ND3+ IONS IN K2YF5 AND LIYF4 CRYSTAL HOSTS

The Laser Induced Fluorescence (LIF) spectrum of K2YF5:Nd3+ (PFYK:Nd) and LiYF4:Nd3+ (YLF:Nd) single crystals, pumped by the fluorine F-2 pu lsed discharge molecular laser at 157.6 nm, was obtained in the Vacuum Ultraviolet (VUV) region of the spectrum. The fluorescence peaks were assigned to the 4f(2)5d --> 4f(3) dipole allowed transitions of the N d3+ ion. The 180 nm band of the LIF spectrum from the crystals indicat es that the 4f(2)5d --> 4f(3) dipole transitions originate from the lo w Stark components of the K-4(11/2) level of the 4f(2)5d configuration . The absorption spectrum of the crystal samples in the VUV was obtain ed as well and spectroscopic assignment of the levels of the 4f(2)5d c onfiguration was made. The electric crystal field splits all the level s of single and mixed configuration. The energy of the Stark component s of the 4f(2)5d configuration in YLF:Nd was shifted by few hundred cm (-1) relative to that of PFYK:Nd. We observed eleven and nine dipole t ransitions, between the 4I(9/2) ground level of the 4f(3) configuratio n and the Stark components of the levels of the 4f(2)5d configuration of the Nd3+ ion, in YLF and PFYK crystal hosts, respectively. (C) 1998 Elsevier Science B.V.