由于激光棒具有细长的特殊形貌特征，传统的双通测试方法虽然灵敏度较高，但是往往存在明显的衍射效应和多重成像导致的边缘黑环，这会导致有效测量面积的缩减，对于小口径光学元件的测量尤为不利。为了克服这一缺陷，采用单通法测量激光棒的波前畸变，使用直角棱镜作为反射件，使得测试光仅通过激光棒一次，从而减少光路中的等效圆孔数和成像次数，抑制衍射和边缘重叠。利用展开的多小孔模型讨论了衍射效应的影响，并且从成像角度讨论边缘重叠的成因，从而得出单通法的优势。另外，为使参考光与测试光的匹配，需要将直角棱镜旋转至少5.40°偏摆角以提高干涉条纹的对比度。最终测得激光棒波前畸变的峰谷值为0.068λ，均方根值为0.012λ。

Due to the special shape characteristic of a laser rod, the traditional double-pass test method, which has high sensitivity, tends to have obvious diffraction effect and edge black ring caused by multiple imaging. The result leads to the reduction of the effective measurement area, which has a negative impact particularly on the measurement of small aperture optical components. To avoid these problems, the wavefront aberration of laser rod is measured by the single-pass method. The right-angle prism is used as the reflection part to ensure the test light passes through the laser rod only once, so that the number of equivalent circular holes and the imaging times can be reduced. We use the expanded multi-hole model to discuss the diffraction effect and analyze the cause of edge overlap from the perspective of imaging to derive the advantages of the single-pass method. In addition, considering the matching of the reference light and the test light, it is necessary to rotate the right-angle prism by at least 5.40° to improve the contrast of the interferogram. Finally, the measurement result of the laser rod wavefront was as follows: the peak-valley value is 0.068λ and the root mean square is 0.012λ.