镁离子内扩散铌酸锂表面改性研究

STUDY ON SURFACE MODIFICATION OF LITHIUM NIOBATE INDIFFUSED WITH MAGNESIUM IONS

利用溶胶－凝胶工艺在Ｙ切铌酸锂单晶基片衬底上制备氧化镁薄膜，经镁离子内扩散后，进行了其表面改性研究。由Ｘ射线衍射和电子探针显微分析表明，扩散层具有一种新的化合物结构特性，镁离子浓度随扩散深度的变化具有近似半抛物线形状的分布。本实验结果可用于铌酸锂单晶光纤芯－包层波导结构，经选择适当的参数如膜厚、扩散温度、扩散时间等，可望得到晶纤的单模传输。

Magnesium oxide thin films on Y-cut lithium niobate single crystal substrate are prepared by sol-gel processing then,a Mg-ion indiffusion process is applied to study its surface characteristics.By means of X-ray diffraction and electron probe micro-analyses,it is shown that diffused layers have a characteristic crystallo-graphic structure of a new compound and the Mg-ion concentration has a nearly half parabolic profile with dif-fused depth.These results obtained in this study can be used to form the core-cladding waveguide structure of lithium niobate single crystal optical fiber and obtain single mode propagation by choosing suitable parameters such as film thickness,diffusion temperature,diffusion time,crystal fiber diameter,etc.