Zonal wavefront reconstruction with multidirectional difference wavefronts for multilateral shearing interferometers

Wavefront reconstruction is a key step in multilateral shearing interferometers, directly influencing measurement accuracy. Conventional zonal reconstruction methods typically use only two orthogonal difference wavefronts, which limits measurement accuracy. In this paper, we innovatively propose a zonal wavefront reconstruction method that utilizes multidirectional difference wavefronts, comprehensively considering all difference wavefront information in the interferogram. By incorporating two diagonal difference wavefronts into the wavefront expression at specific grid points, we construct a multidirectional reconstruction equation that includes vertical, horizontal, diagonal, and anti-diagonal directions. This method provides a more accurate description of subtle wavefront variations, improving measurement precision and noise immunity. Simulation tests demonstrate that this approach achieves high reconstruction accuracy across a broader range of shear ratios and exhibits better noise immunity than the traditional zonal method. Furthermore, experimental platforms for the null test and the dynamic response test using quadriwave lateral shearing interferometry are established. Experimental results indicate that, compared to the traditional zonal reconstruction method, the proposed method enhances the absolute measurement precision of quadriwave lateral shearing interferometry from 0.0065<i>λ</i> to 0.0048<i>λ</i> RMSE (<i>λ</i>=635<i>n</i><i>m</i>). The method exhibits superior linear response and higher detection accuracy in aberration measurement, fully confirming its practicability and effectiveness. This research has significant application value and research implications in the field of surface detection and aberration analysis of optical systems.