Complex optical component measurement with ptychography

The extended Ptychography iterative engine (ePIE) has the advantages of fast convergence and high imaging accuracy, and is widely used in quantitative phase imaging. In the measurement process of complex optical components, the coherent diffraction imaging may get stuck in local optima and stop converging, resulting in incorrect reconstruction results. To increase the convergence speed, a hybrid algorithm method was proposed, which improves convergence speed and reduces computation time. The principle of this method is the mixed reconstruction of Ptychographic iterative engine (PIE) and ePIE. By adjusting the proportion of PIE and ePIE in iterative calculations, the probe and the object can be reconstructed to the global optimal value simultaneously. In the experiment, a random phase plate with a minimum structure size of 9.6×9.6 micrometers was measured. The experimental results demonstrate that compared to the ePIE algorithm, this algorithm can significantly improve convergence speed and converge to global optima. This article proposes an accelerated convergence method based on Ptychography, which provides a solution for high-precision and complex distributed object measurement.