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

Laser-active (or potentially laser-active)(F2+)H centres have been inv estigated in NaCl:O2-, NaCl:S2-, NaCl:Se2-, KCl:O2-, KCl:S2-, KBr:O2-, KBr:S2-, KI:O2-, KI:S2- and RbCl:O2-. In four of these crystals, (F2)H centres were previously either entirely unknown or only allusively mentioned in the literature. Preparation procedures are described; abs orption and emission spectra are studied, including zero-phonon lines when they exist. The stability of the centres in the dark at room temp erature is also measured, since it is an important property for the ev entual use of these centres as the active element of tunable lasers.