Interferogram-driven Method for Large-Gradient Wavefront Reconstruction

To address the challenge of inaccurate wavefront reconstruction caused by excessively dense interference fringes, this paper proposes an interferogram-driven method for large-gradient wavefront reconstruction. In this method, the interferogram serves as the optimization target, while the Zernike polynomial coefficients are treated as the optimization variables. By constructing an iterative optimization framework using the structural similarity index (SSIM) as the evaluation metric, the particle swarm optimization (PSO) algorithm is employed to iteratively update the Zernike coefficients. This process drives the simulated interferogram to gradually converge toward the target interferogram, thereby achieving the reconstruction of large-gradient wavefront. Simulation and experimental results demonstrate that, as long as the interferometric modulation has not undergone complete collapse and no dark regions appear in the interferogram, the proposed method can achieve accurate reconstruction of large-gradient wavefronts. The reconstructed surface shape obtained by this method is highly consistent with that measured by a ZYGO interferometer, with the absolute PV and RMS surface errors better than lambda/50 and lambda/200, respectively, verifying the accuracy and reliability of the proposed approach.