To confirm the existence of at least two types of Yb 3+ optical centers in YScO3, the timeresolved luminescence spectra were measured (Figure ). By increasing the time delay (tdel) from 40 µs to 1.58 ms, the intensities of the Yb 3+ ion fluorescence lines with maxima at νmax. = 9775, 9632, 9320 cm -1 were redistributed. Specifically, an increase in intensity was observed for the luminescence line with maxima at νmax. = 9737 and 9320 cm -1 , while a decrease in intensity was observed for the line with maxima at νmax. = 9625 cm -1 . -10235 cm -1