EFFECTS OF GAMMA-IRRADIATION AND ANNEALING TREATMENTS ON THE PERFORMANCE OF CR-TM-HO-YAG LASERS

Spectroscopic studies of Cr;Tm;Ho:YAG (CTH:YAG) crystal samples after succesive procedures of gamma irradiation and annealing, were carried out. The emission characteristics of the free-running laser, doped wit h these ions were measured. Mechanisms which cause changes of the lase r properties are discussed. Previously observed favourable changes of the optical and laser emission properties induced by thermal annealing and gamma radiation, are also confirmed. In particular, a substantial lowering of the emission threshold of the laser (after annealing) as well as an increase of the pumping efficiency (after gamma exposure) w as obtained. It is argued, that this last effect is due to the sensiti zation process of the active Ho3+ ions. (C) 1998 Elsevier Science B.V. All rights reserved.