The present work is devoted to investigation of optical absorption changes in Fe and Cu doped LiNbO3 (LNO) single crystals induced during annealing in vacuum and air as well as under influence of the 209 Bi ions irradiation with energy 11.4 MeV/u (MeV per nucleon) and a fluence 5 × 10 11 cm −2 at room temperature. The analysis of changes of absorption of the crystal during air annealing have been studied in the Arrhenius coordinates and activation energies have been determined.