周期极化LiNbO_3晶片的制备工艺研究

A Study of the Preparation of Periodically Poled LiNbO_3

采用外加电场法制备了周期极化LiNbO3单晶(PPLN),实现LiNbO3单晶周期极化的反向脉冲为24.3 kV/mm,单个脉冲宽度为30 ms,脉冲个数为50个。系统研究了脉冲波形、电极形状对周期极化的影响,实验结果证明,框形电极是克服高电压作用下LiNbO3晶片击穿严重的有效方法,成品率是采用梳状电极的5倍。选择合适的脉冲波形对成功制备周期极化的LiNbO3晶体有着极其重要的作用。采用上升时间为5 ms的方形脉冲极大地改善了高电压作用下的边缘被打碎而引发的边缘击穿,及由晶片中间部分出现微细裂纹而引发的体击穿。

The periodically poled LiNbO3 （PPLN） was prepared by applying external field. Fifty pulses were operated on LiNbO3 to prepare PPLN,each single pulse is 24.3 kV/mm for 30 ms. The influence of wave form and periodic electrode on periodic poling had been studied systemically. It was found that the frame-like periodic electrode had positive effect on overcoming fringe breakdown, the ratio of finished product was five times than using comb-like periodic electrode. It was also found that the poling voltage waveforms play an important role in preparation,the fringe breakdown and bulk breakdown could be overcomed by using square pulse with a rise-time of 5 ms.