| Popis: |
A strong population of excited F-center states is achieved in various alkali halides using a short intense pulse of a Q-switched Ruby laser. During the presence of the excited F-centers the time dependence of their decay is measured with a fast-recording spectrometer. This is done by monitoring the absorption changes connected with the ground state or excited state popula tions. Using this method for crystals containing low F-center concentrations the lifetime of the excited state of F-centers in KI, RbI, CsI, RbBr and CsF is measured from 7K to about 80K by monitoring absorption changes in the region of the beta-, the beta-* and the F-band, respectively. For KI samples containing high F-center concentrations it is found that the decay curves are nonexponential. (Author) |
