中文摘要：

声光波导光开关可以作为高速光通信网络中的开关器件，其中光纤一器件对接耦合损耗大是影响其性能的主要因素。从光波导模场椭圆度和不对称度对模场失配引起的耦合损耗出发，计算Ti：LiNbO3波导与光纤耦合损耗最小时对应的最佳Ti离子扩散深度。分析得到不同切型的Ti：LiNbO3波导中扩散深度、光纤模场半径对耦合损耗的影响。结果表明，y切Ti：LiNbO3波导耦合损耗约为Z切波导的3倍。研究结果为共面型声光波导调制器中光波导制作参数的设计提供帮助。

英文摘要：

Guided acousto-optic switch is the key device in optical communication networK, for me guided devices, great coupling loss between waveguide devices and single-mode optical fibers is the main factor which affects its performance. By analyzing mode eccentricity and asymmetry, a method used to calculate the optimum diffusion depth for minimum coupling loss is presented. In different cut-type waveguides, the impact of diffusion depth and fiber mode field radius on coupling loss is analyzed. The results show that coupling loss of y-cut Ti：LiNbO3 waveguide is 3 times that of z-cut waveguide. Some valuable results for the design of optical waveguide in guided acousto-optic devices are obtained.