Compressive holography aided multi-slice ptychography

Multi-slice imaging can obtain the Three-dimensional (3D) information of thick objects by modeling specimen as a number of slices. This approach can be applied to biomedical imaging, integrated circuit inspection and sample thickness measurement. Multi-slice ptychography is a full-field and lensless imaging method exploiting 3D Ptychographic Iterative Engine (3PIE) algorithm to reconstruct the complex-value function of object planes and illumination beams simultaneously. Even though this method does not require prior knowledge, inaccurate initial guesses of the object planes lead to more iterations than for a single-slice object. Compressive Holography (CH) is another method for reconstructing multi-slice objects. It enables to obtain 3D information from a single 2D Gabor hologram by Compressive Sensing (CS) algorithm. In this paper, both methods are combined, and the corresponding algorithm is proposed, in which the reconstructed multi-slice object by CH is adopted as the initial guess for object planes in 3PIE providing a more accurate initial value. Experimentally, the ptychography data set and a single in-line hologram are recorded in sequence. The numerical simulation studies on double-slice and three-slice objects were conducted, respectively. Numerical simulation results indicate that our method has a smaller error compared to traditional methods and it can improve the convergence speed. The proposed method was experimentally demonstrated using a double-slice object. The conclusions drawn from the experiments are in agreement with the simulations. We expect our method to provide invaluable information for both the life and materials sciences.