Abstract
In this paper, Fe-doped lithium niobate crystals with different Li compositions are prepared. The composition and temperature dependence of the light-induced scattering in Fe-doped lithium niobate are studied. The results show that the crystals with the compositions lower than 49.0 mol% suffer from the serious light-induced scattering, but when the composition increases to 49.3 mol% the light-induced scattering is suppressed significantly, in particular at a composition of 49.8 mol% the light-induced scattering disappears completely. It is also found that the light-induced scattering of the crystals with lower compositions can be suppressed completely by elevating the temperature to 150 degrees C. However the temperature for the complete suppression of the light-induced scattering in the crystal with a composition of 49.3 mol% is only 80 degrees C. Based on these results, it is suggested that a critical Li composition may exist in a range from 48.9 mol% to 49.3 mol% and beyond this composition the suppression and temperature dependence of the light-induced scattering will change significantly.