Effect of growth conditions on the domain structure of LiNbO3〈Gd〉 single crystals

The domain structure of LiNbO3〈Gd〉 single crystals grown under steady-and unsteady-state conditions has been studied using Thixomet, a high-speed, flexible image analysis system. The results have been used to formulate the growth conditions of (1) doped lithium niobate single crystals with a modulated dopant distribution and, accordingly, a regular domain structure, whose period is determined by the ratio of the pull rate to the crystal rotation rate, and (2) doped lithium niobate single crystals with a sufficiently uniform dopant distribution along the growth direction, without any regular domain structure.