Evaluation of Mn\u3csup\u3e5+\u3c/sup\u3e-doped Sr5(VO4)3F as a laser material based on excited-state absorption and stimulated-emission measurements

Abstract

Excited-state absorption and stimulated-emission measurements of Mn5+-doped Sr5(VO4)3F were made with a pump-and-probe technique. Strong excited-state absorption bands were observed, corresponding to the transitions from the 1E(1D) metastable level to higher-lying singlet levels. The stimulate emission from the 1E(1D) level to the 3A2(3F) ground state is overlapped by a tail of the 1E(1D)→1T2(1D) excited-state absorption band. The cross section of the 1E(1D) → 1T2(1D) transition at 1161 nm is (1.4 ± 0.3) × 10-20 cm2 for E∥c and (2.4 ± 0.5) × 10-20 cm2 for E⊥c. The ratio between the excited-state absorption and the stimulated-emission cross section at 1161 nm is 0.52 for E∥c and 1.82 for E⊥c. Therefore laser emission is expected to be inefficient in E∥c polarization and not to be possible in E⊥c polarization. The crystal field parameters in the cubic field approximation were determined to be Dq = 1134 cm-1, B = 356 cm-1, and C = 2918 cm-1, giving Dq/B = 3.19 and C/B = 8.20. © 1997 Optical Society of America