Alexandrite laser pumped LiF:F2− laser

Abstract For the first time to our knowledge a direct alexandrite laser pumping of LiF:F 2 − crystals was suggested and realized by means of energy transfer from the F 3 − to the F 2 − color centers (CCs). Tunable laser oscillation of LiF:F 2 − in the 1000–1300 nm spectral range with a maximum efficiency of 10% was achieved. The process of two-step photo-ionization of the F 3 − CCs under 740 nm excitation was demonstrated experimentally on the basis of the measured decay rate of F 3 − centers. The photo-ionization cross-section from the first excited level of F 3 − centers was calculated to be 2×10 −22 cm 2 . Stable output lasing of the LiF:F 2 − laser at room temperature under 793 nm excitation was predicted and realized.