铁电铌酸钾锂晶体的生长

Growth of Ferroelectric Potassium Lithium Niobate Crystals

用电阻加热引上法生长了不开裂、全透明的具有倍频性能的铌酸钾锂（ＫＬＮ）晶体。研究了影响晶体开裂的主要因素和晶体生长的稳定性。发现用引上法生长ＫＬＮ晶体时，要得到全透明、不开裂的ＫＬＮ晶体，熔体中Ｌｉ２Ｏ的含量应该低于２６．５ｍｏｌ％，拉速应低于０．５ｍｍ／ｈ，以及生长过程中应该选择凸的固液界面以保证晶体生长的稳定性。在Ｌｉ２Ｏ含量较高的熔体中生长ＫＬＮ晶体时，［１００］取向的籽晶比［００１］取向的籽晶更有利于晶体生长。用由Ｌｉ２Ｏ含量为２６ｍｏｌ％的熔体中沿［１００］取向生长的ＫＬＮ晶体对Ｔｉ∶Ａｌ２Ｏ３激光器输出的８２０ｎｍ的激光倍频。

The crack free and full transparent potassium lithium niobate (KLN) crystals with frequency doubling performance have been grown by means of the resistance heating Czochralski (CZ) technique.The influence factors of crystal cracking and the stability of crystal growth have been studied.In order to obtain the crack free and full transparent KLN crystals by the CZ technique,the Li 2O content in melt should be less than 26.5mol% and the pulling rate should be lower than 0.5mm/h as well as selecting a axis seed was necessary.And also it was necessary to keep convex shape of solid liquid interface for the stability of the crystal growth.We have realized the blue light output at 410nm by doubling the 820nm light wave generated from Ti∶sapphire laser.