通过一维低频液体表面波激光衍射实验，得到了稳定、清晰的衍射图样。当入射光的方向与表面波的传播方向共面时，衍射图样的分布方向位于该平面。当入射光的方向与表面波的传播方向不共面时，衍射图样的分布方向与入射光不共面。通过建立适当的坐标系，理论上导出了空间斜入射一维表面波的衍射公式，并进一步得到衍射图样分布方向与激光入射角之间的关系。最后通过计算得到表面波的波长，并与其他运算方法（液体色散关系）得到的结果进行对比，两者结果十分吻合。

The stable and clear diffraction patterns were obtained by an experiment of laser diffraction from 1-D liquid surface acoustic wave (SAW) excited at low frequencies. When the incident direction of laser and the propagation direction of SAW are in same plane, it is observed that the distribution direction of the diffraction patterns is also located in this plane. However, when the incident direction of laser and the propagation direction of SAW are not in same plane, the distribution direction of the diffraction patterns is not located in the plane with the incident light. The formula of laser diffraction from one-dimensional SAW in oblique incidence was theoretically derived by the aid of the establishment of the proper coordinate system. Furthermore, the relation between the distribution direction of the diffraction pattern and the incidence angle of the laser was also achieved. The wavelength of SAW was obtained by the calculation of the data from the experiment and it agrees with the results obtained by the other methods.