Cross-relaxation processes and structural modifications in Ga-Ge-S:Er3+ chalcogenide glasses

Various processes of non-radiative energy transfer between erbium ions in Ga-Ge-S:Er3+ chalcogenide glasses using the time-resolved luminescence spectroscopy are considered. The evaluation of the energy transfer constants CSA and CSS for the 4I9/2, 4F9/2 and 4S3/2 Er3+ levels is presented. The variation of the studied glasses structure with an increase of erbium ions concentration is shown by means of estimation of the minimum distance between Er3+ ions as permitted by the glass matrix (Rmin).