研究了514 nm可见激光诱导掺铪摩尔分数为3%同成分铌酸锂晶体优先畴成核。利用数字全息干涉术实时记录监测激光诱导优先畴成核过程,再现了该过程中晶体内诱导区域相位分布的变化,通过测量证实成核场随诱导光强的增强呈指数减小。在实验基础上提出诱导过程中出现的沿Z方向的空间电荷场对激光诱导优先畴成核有着非常重要的影响,并给出了激光诱导铌酸锂晶体优先畴成核定性的物理模型。不仅能够为激光诱导晶体铁电畴工程的优化提供重要信息,而且能够为激光诱导铌酸锂晶体优先畴成核机制的研究提供重要实验依据。

The 514 nm visible laser-induced preferential domain nucleation effect is investigated in the 3% mole fraction hafnium-doped lithium niobate crystal.The local variation of phase distribution during the laser-induced preferential domain nucleation is in-situ recorded and is reconstructed by the digital holographic interferometry.The nucleation field decreases exponentially with increase of irradiation intensity.The space-charge field along Z direction has an important influence on the laser-induced preferential domain nucleation.According to the experimental results,a qualitative model for the laser-induced preferential domain nucleation process in lithium niobate crystal is presented.This model not only provides the essential information for the future optimization of laser-induced domain engineering,but also supplies the new experimental evidences for the future mechanism investigation of laser-induced domain nucleation in LiNbO3.