ARTICLES: Spectral, luminescence, and lasing properties of a yttrium scandium gallium garnet crystal activated with chromium and erbium

A study was made of the spectral, luminescence, and lasing properties of an yttrium scandium gallium garnet crystal activated with chromium and erbium. The lifetimes of the Stark sublevels of some of the levels of Er3+ were determined and the schemes of these sublevels were constructed. It was established that, in addition to the "forward" energy transfer, there was also the reverse process Er3+→Cr3+. The mechanism of the interaction and its microscopic constants were determined. The chromium and erbium concentrations could be varied within wide limits without significant deterioration in the conditions for the transfer of energy from Cr3+ to the 4I11/2 level of Er3+. A study was made of the lasing properties of this crystal (λl = 2.80 ± 0.01μ) under free-running and Q-switching conditions.