Topography detection method of microlens array based on improved TIE

The optical performance of the microlens array (MLA) is closely related to its surface topography characteristics. However, at present, most of the methods for detecting the morphology of microlens arrays by using profilometers or confocal microscopes for individual scanning, although they can effectively detect the morphology of sub-lenses, are not only costly but also inefficient. At present, for the morphology detection of microlens arrays, a high-precision and rapid detection method has not yet been formed. This study proposes a novel detection method based on error compensation for the phase recovery technology of the improved intensity transport equation (TIE). By constructing the sub-lens phase modulation matrix and achieving surface parameter inversion, a non-contact rapid detection method for the surface topography of microlens arrays was established. The numerical simulation results show that the structural similarity index (SSIM) between the underground section reconstructed by the improved intensity transfer equation algorithm and the theoretical model is 0.9716, verifying the accuracy of the algorithm. The experimental measurement results of the microlens array show that, compared with the SSIM of the ideal model, the reconstructed phase is between 0.65 and 0.82, opening up a new technical approach for the quality inspection of micro-optical components.