为满足波面剪切干涉和双细光束干涉曲反射表面非接触精密测量、台阶高度测量以及其他平行分光需要，利用双折射晶体特性，研究并设计了一种单一平板激光平行分束器。当一束激光入射到双折射晶体时，它的2个相互正交的的偏振分量将有不同的折射特性，因此特定晶轴方向和厚度的晶体平行平板可以实现入射光束的平行分束。描述了双折射晶体平行平板的分束原理，推导了分束距离与光轴方向、晶体厚度、入射角的关系，分析了分束距离随主要设计参数的变化规律。采用设计的晶体激光分束器进行了实验测试，验证了分析与实测结果的一致性。

A parallel laser beam splitter was designed based on the characteristics of birefringent crystal for applications such as wavefront shearing interference,dual light beam curved reflective surface measurement and step height measurement. When a plane wave or laser beam enters a birefringent crystal,its mutually perpendicular polarization components will propagate in different states to generate two beams after they exit the crystal. The splitter consists of a single crystal plate. Its splitting principle was described,and the relationship between the splitting distance,the direction of optical axis,the thickness of the plate,and the incidence angle was deduced. The variation law of splitting distance with the main design parameters was analyzed. Lab test was conducted on the splitter,and the analysis results were verified.