For the first time to our knowledge a direct alexandrite laser pumping of LiF:F2- crystals was suggested and realized by means of energy transfer from the F3- to the F2- color centers (CCs). Tunable laser oscillation of LiF:F2- in the 1000-1300 nm spectral range with a maximum efficiency of 10% was achieved. The process of two-step photo-ionization of the F3- CCs under 740 nm excitation was demonstrated experimentally on the basis of the measured decay rate of F3- centers. The photo-ionization cross-section from the first excited level of F3- centers was calculated to be 2 × 10-22 cm2. Stable output lasing of the LiF:F2- laser at room temperature under 793 nm excitation was predicted and realized. © 2001 Elsevier Science B.V. All rights reserved.