采用双层（ＢｉＡｌ）ＹＩＧ膜结构来制作单模磁光波导。通过改变外延生长工艺来调节两层薄膜的折射率，可在一定波导的厚度范围内实现单模传输。Ｘ射线衍射测量表明薄膜质量良好，且易磁化方向平行膜面，最后利用棱镜耦合，观察了波导中的暗ｍ线。 Double-layer (BiAl) YIG film structure to produce single-mode magneto-optical waveguide. By changing the epitaxial growth process to adjust the refractive index of the two films can be achieved within a certain waveguide thickness single-mode transmission. X-ray diffraction measurement showed that the film quality is good, and the direction of easy magnetization parallel to the film surface, and finally the use of prism coupling, the observation of the waveguide m dark line.