Investigation of Cr-doped MgO and Sc2O3 as potential laser sources for the near infrared spectral range

Cr-doped MgO and Sc 2 O 3 were spectroscopically investigated with respect to their feasibility as solid state laser materials. The crystal field parameters of the octahedrally coordinated Cr 3+ were determined to be Dq = 1615 cm -1 , B = 586 cm -1 , and C = 3249 cm -1 , thus Dq/B = 2.75 and C/B = 5.54 for Cr 3+ : MgO and Dq = 1490 cm -1 , B = 590 cm -1 , C = 3227 cm -1 , thus Dq/B = 2.53, and C/B = 5.47 for Cr 3+ : Sc 2 O 3 . The Cr 3+ emission in these crystals covers the spectral region between 700 nm and 1100 nm. Besides the Cr 3+ -ion, in Sc 2 O 3 another optical active center correlated with chromium is observed. This center exhibits absorption between 750 nm and 1100 nm and emission between 1050 nm and 1800 nm. For Cr 3+ : MgO room temperature, continuous wave laser oscillation under argon ion laser pumping was realized.