腐蚀法研究掺Er熔融石英玻璃的真空热极化

Etching Study of Thermally Poled Er-doped Fused-silica Under Vacuum

掺 Er熔融石英片经过真空热极化后 ,利用 4 0 %的 HF腐蚀其沿极化电场方向的剖面 ,通过原子力显微镜 (AFM)观测到剖面阳极边极化区内出现了峰 -谷 -峰形式的形貌变化 ,研究表明其原因是正负带电离子层的不同腐蚀速度 ,从而得出极化区内离子层分布为负 -正 -负的形式 ,与多载流子模型对真空热极化的解释相一致 ;根据离子层的分布 ,采用双高斯模型模拟出极化区内电场分布 ,并得到与实验结果相当吻合的理论 Maker条纹。

The Er-doped fused-silica coverslips, thermally poled in vacuum, were etched in 40% HF transversely to the poling direction, and the resulted ridge-channel-ridge shaped poled region was observed by AFM. This kind of etched shape results form the different etched rates of the positive and negative charge layers corresponding to the channel and ridge respectively. The negative-positive-negative space-charge distribution in the poled region can be proved by the multiple charge model. For the first time we made use of the two-Gauss model to fit the electrical field in the poled region and a theoretical best-fit Maker fringe was obtained.