Radiation effects and defects in solids
Persistent spectral hole-burning in electronic tranisitions of different types of lattice defects
T. Attenberger, Ilmo Sildos, Glynn D. Jones, Udo Bogner, Max Maier
Abstract
With a ring dye laser persistent spectral hole-burning was measured by fluorescence excitation spectroscopy in the zero-phonon lines of the 2llg ↔ 2llu transition in KI:S2 − and of the 3H4 → 3P0 transition of a defect center with three D− ions in SrF2:Pr3+:D−and also in the zero-phonon line at 462.5 nm of a color center in neutron-irradiated and annealed α-Al2O3. In all three lines holes with a width in the order of 1 GHz could be obtained at 1.5 K with single frequency laser. With broad-band laser in KI:S2 − and SrF2:Pr3+:D− spectral redistribution within the full range of inhomogeneous broadening could be observed which are explained by a photophysical model based on barrier crossing in asymmetric double-well-potentials. In the case of sapphire a photobleaching process is dominant which is effective also for nonselective excitation, and the holes are thermoresistant up to 300 K.