Oliver S. Wenger, Hans U. Güdel and Stefan Kück
Excited-state absorption of Cr³⁺ in Cs₂NaScCl₆
J. Chem. Phys. 117, 909-913 (2002)                 

Abstract: Excited-state absorption (ESA) measurements on Cr³⁺ doped Cs₂NaScCl₆ in the 6300-17500 cm^–1 spectral region at 15 K and 300 K are reported. Two ESA bands due to ⁴T_2g ⁴ T_1g(⁴F) and ⁴T_2g ⁴ T_1g(⁴P) transitions are observed. The large bandwidth of the t_2g²e_g-intraconfigurational ⁴T_2g ⁴T_1g(⁴F) transition at 15 K is rationalized using a single configurational coordinate model involving the e_g Jahn-Teller coordinate. At 15 K the effective peak stimulated emission cross section at 10 870 cm^–1 is about 3.5×10^–20 cm², and there is essentially no overlap with ESA at this temperature. At 300 K the ESA cross section is larger than the stimulated emission cross section over the whole range of spontaneous emission.