Laser-selective excitation and polarisation studies of BaF2: Tm3+ single crystals
Presented by Dr. Marjorie MUJAJI on 11 Jul 2014 from 11:30 to 11:50
Type: Oral Presentation
Track: Track A - Division for Physics of Condensed Matter and Materials
Site-selective laser excitation studies of BaF<sub>2</sub>:Tm<sup>3+</sup> single crystals performed at temperatures ranging from 10 K to 75 K are reported. There is a single dominant centre at the dopant concentrations of up to 0.1 mole% used. All the crystal-field energy levels for three multiplets (<sup>3</sup>H<sub>6</sub>, <sup>3</sup>H<sub>4</sub> and <sup>3</sup>F<sub>2</sub>) of the centre and the fluorescence lifetime of the <sup>3</sup>H<sub>4</sub> multiplet are presented. From polarisation ratio measurements in <111>-oriented crystals the dominant centre is confirmed to be of C<sub>3v</sub> symmetry, with the charge-compensation interstitial F<sup>-</sup> ion in the next nearest neighbour position to the Tm<sup>3+</sup> ion. Symmetry labels (irrep labels) have been assigned to the crystal-field energy levels. Vibronic coupling is apparent.