SPECTROSCOPIC PROPERTIES OF [F-2-DOPED AND SULFUR-DOPED ALKALI-HALIDES(](AH) CENTERS IN OXYGEN)

In search of potential laser-active colour centres, we have created an d spectroscopically studied for the first time (F2+)AH centres in KCl: Li+:O2- and RbCl:Na+:O2-. We compare them with the 'classical' (F2+)AH centres in KCl:Na+:O2- and KBr:Na+:O2-. We describe preparation proce dures, and absorption and emission spectra at 100 and 5 K. We study th e stability of the centres in the dark at room temperature, an importa nt property for laser applications. Preliminary data concerning (F2+)A H centres in KBr:Na+:S2- are also reported.