激光晶体Nd:KGW晶体的表面缺陷观察

Observation on Surface Defects of Laser Crystal Nd:KG W

本文采用助熔剂籽晶提拉法生长出了Nd :KGW激光晶体。利用光学显微镜对晶体表面进行观察、并拍摄到晶体裂缝、生长丘、生长条纹和包裹物等缺陷的照片。分析其原因 ,是由于晶体生长工艺的不稳定 ,尤其是晶体生长过程中的温度梯度不够合适、提拉速度过快、降温速率偏快等所致。并由于生长体系粘度较大 ,容易形成包裹 ,晶体包裹物经XRD分析认为其中主要是熔体。

In this paper Nd:KGW crystal has been grown by means of seed pulling in flux under polarizing microsoope.The defects in crystal,including cracking,hillocks,growth fringe,growth steps and inclusions were observed.The reason for caused defect in crystal can be explained by the instability of the growth process,such as the unsuitable temperature grads,excessive high speed in growth and cooling,etc.Besides it is easier to result in inclusion because of high viscosity in this system,XRD indicated that most of the inclusion was flux.