Self-consistent analysis of absorption and emission data forF A centres in alkali halides

Direct determination of site symmetry forF A centres in alkali halides

“…Maxwell equations, taken for the slowly varying envelope of E vector of the electromagnetic wave, may be written in the form [2] (3) az where ~, s = n~, 2 + i~, 2 is the resonant defect contribution to the complex refractive index and ~l,s = ~c N0.1, s(oJ), 20) in which N is the concentration of FA centres, and c is the velocity of light.…”

“…One of these techniques is the non-linear polarization spectroscopy developed for resonant absorption Ill and infrared luminescence [2] of reorienting defects in cubic crystals. One of these techniques is the non-linear polarization spectroscopy developed for resonant absorption Ill and infrared luminescence [2] of reorienting defects in cubic crystals.…”

“…Therefore, the present technique for the determination of ~ parameter is very informative in this band. The parameter ~ was interpreted in a previous work [2] as reflecting the effect of a tilt angle between the FA centre dipole and the crystalline axis, and the effect of the overlap between FA1 and FA2 bands. Such a result is in agreement with previous estimates[l] deduced from the same kind of experiments and can be compared with known data from photoluminescence measurements [18][19][20].…”