Spectroscopic and laser properties of Cr<sup>3+</sup>-doped Al<inf>2</inf>(WO<inf>4</inf>)<inf>3</inf>and SC<inf>2</inf>(WO<inf>4</inf>)<inf>3</inf>

Different tungstates and molybdates have been examined in view of their potential application as host lattices for tunable Cr ³⁺ solid-state lasers. From chemical, crystal growth, and structural considerations, Cr:Al 2 (WO 4 ) 3 and Cr:Sc 2 (WO 4 ) 3 are suitable and have been investigated spectroscopically in detail. Due to the acentric site symmetry of the Cr ³⁺ laser ions (C 1 ), both compounds exhibit strong absorption and emission cross sections in the 10 ^-19 cm ² range and therefore belong to the class of high-gain Cr materials. For the first time, laser action has been observed in Cr : Al 2 (WO 4 ) 3 at about 800 nm wavelength. Laser experiments with Cr:Sc 2 (WO 4 ) 3 are in progress.