在全反射中研究了发散波束在两种不同媒质界面上Goos-H(a)nchen位移与焦移.首先,通过建立发散光束全反射简单光线模型来显示焦移的形成.然后,从波动光学出发,利用Fourier光学中的角谱法推导出Gauss发散波束入射下Goos-H(a)nchen位移和焦移的近似关系式.结果表明,由Ciglia 和 Brownstein 针对于均匀波束提出的Goos-H(a)nchen位移和焦移的微分关系式同样也适用于Gauss发散波束入射的情况.最后,通过数值模拟总结出了焦移的一些不同于Goos-H(a)nchen位移的特殊性质.这些特殊性质的发现为改善现有实验和工程精度提供了新路径.,In this paper, the Goos-H(a)nchen and Focal Shift of a diverging beam at an interface of two different media is investigated by means of establishing simple expanding ray model and the Fourier optics method of angular spectrum in total intal reflection.These approaches predict the shift. Moreover, the differential expression of the relationship between is the same as Ciglia and Brownstein’s results. Finally, we have discovered some properties of the focal shift based on numerical analysis, way for experiments and engineering to improve their precision.