LIGHT-INDUCED NIR-ABSORPTION IN SR0.61BA0.39NB2O6-CE AT LOW-TEMPERATURES

Absorption measurements of Sr0.61Ba0.39Nb2O6:Ce under visible light (A r+, -Kr+ laser or XBO-lamp) illumination show a light-induced broadban d NIR-absorption with maximum at 1.6 mu m. This absorption is very pro nounced at temperatures below 150 K. Its lineshape is similiar to the broadband absorption which is being observed in reduced SBN crystals. The time dependence of the light induced NIR-absorption after switchin g off the laser light can be fitted by an addition of two exponentials . The temperature dependence of these time constants is not Arrhenius like indicating several interaction mechanisms.