6533b85ffe1ef96bd12c193e

RESEARCH PRODUCT

Optically detected magnetic resonance studied via the blue luminescence of Ti-doped

subject

description

The UV-excited blue and green luminescence bands of Ti:sapphire are characterized by ODMR. These emission bands are attributed to two centres, which show very similar properties and are created as a result of a charge-transfer transition of an electron from to ions. In both centres, the d electron of and the hole of are strongly coupled and form triplet states. Doublet systems can be ruled out as sources of the blue-green luminescence. The angular dependence of the ODMR can be explained with an appropriate spin Hamiltonian assuming orthorhombic local symmetry. The orientation of the principal axes of the g-tensor and the crystal-field tensor, found for both centres, suggest that the hole is localized on a single oxygen ion and that the bond is almost aligned with the Al-O bonds of the undisturbed lattice.