建立了一种基于偏振掩膜板与环形共路结构的点衍射干涉仪, 通过旋转偏振片可以改变参考光与测试光之间的相对光强, 实现干涉条纹对比度的调节, 能够获得最高对比度的干涉条纹, 并且针对条纹对比度进行了详细的理论分析; 由于系统中线性载频幅度极易调节, 可以有效地改善傅里叶变换法的相位提取精度; 验证性实验被完成。

A point-diffraction interferometer is established, which is based on a polarizing mask and the circular common-path setup. The fringe visibility can be adjusted by rotating the polarizer to change the relative intensities between the test and the reference beams. The fringe pattern with the highest visibility is acquired, and the fringe visibility is also analyzed theoretically in detail. The linear carrier frequency may be easily adjusted in the optical system, so the extraction accuracy of the Fourier-transform method is effectively improved. A validated experiment is accomplished.