Abstract
Fluorescence changes in the sideband shape of selectively laser-excited dyes in amorphous matrices, e.g., polymers and organic glasses, have been observed at different periods of laser irradiation at 1.3 K. The resulting "difference spectra" and also spectra obtained after laser irradiation with a longer wavelength are analyzed. These results and additional photon and phonon effects confirm the model "matrix-shift variations by phonon-induced transitions in two-level systems" introduced to explain the phonon memory.