AbstractOptically stimulated luminescence (OSL) was studied in C-doped α-Al₂O₃ crystals, which had previously been exposed to X or β irradiations. The OSL was excited by monochromatic UV light in 200–300 nm region. Emission maxima appeared at 330 nm and 410 nm which are attributed to F⁺ and F-luminescence respectively. This is supported by measurements of excitation spectra, which showed maxima at 260 and 215 nm. Results were compared to those obtained by measurements of the X-luminescence and phototransferred thermoluminescence in the same samples as well as in pure α-Al₂O₃ crystals. Effects of previous irradiations and of thermal treatment on the OSL intensities were also investigated.