The origin of a fast component of Mn 2+ intra-shell photoluminescence (PL) decay is discussed. We demonstrate that efficient spin-dependent interactions between localised spins of Mn ions and spins of free carriers result in a variation of formation and decay rates of PL emissions in diluted magnetic semiconductors and affect spin selection rules for radiative recombination transitions.Introduction The influence of spin selection rules on rates of radiative and nonradiative recombination transitions is discussed, based on the results of photoluminescence (PL), PL kinetics, optically detected magnetic (ODMR) and cyclotron (ODCR) resonance investigations of ZnMnS, ZnCdSe and CdMnTe crystals, quantum well (QW) and quantum dot (QD) structures. First, the influence of spin-dependent processes on efficiency and on PL dynamics of the Mn 2+ 4 T 1 ! 6 A 1 intra-shell transition in ZnMnS (thin films and bulk samples) and in CdMnTe (bulk, QW and QD samples) is analyzed. Then, we discuss the mechanisms of the ODMR detection and Auger-type nonradiative recombination of bound excitons. Finally, we evidence influence of disorder and of magnetic interactions on rates of exciton formation and recombination in CdTe/CdMnTe and ZnCdSe/ZnSe QWs.

We report on the optical spectroscopy of monolithic fiber preform prepared from nanoporous bismuth-doped silica glass. The experiments reveal the existence of at least two different types of active centers and clearly demonstrate that the presence in the glass matrix of other dopant is not necessary to obtain the near-IR photoluminescence connected to Bismuth.

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