Influence of ionizing radiation on spectroscopic properties of chromium doped forsterite laser crystals

Chromium-doped forsterite single crystals (Cr:Mg/sub 2/SiO/sub 4/) are an active medium for solid-state lasers tunable near-IR region with use of Cr/sup 4+/ and Cr/sup 3+/ ions as active centers. The influence of high-energy electrons irradiation on absorption and luminescence spectra of Cr/sup 3+/- and Cr/sup 4+/-ions in forsterite laser crystals has been studied for the first time. The crystals were irradiated by 21 MeV electrons with fluence varied within the range 7/spl middot/10/sup 13//2/spl middot/10/sup 15/ cm/sup -2/. Gamma irradiation of the crystals with 1 MeV energy and a dose up to 3/spl middot/10/sup 5/ Gy had also been performed.