Biological Sample Imaging by Ptychography with Laterally 1-D Scanning

The most biological samples are transparent and have no amplitude modulation for the incident wave. It is hard to observe the sample without dyeing in traditional microscope. Phase retrieval algorithm can reconstruct complex-valued sample with several diffraction intensity patterns. In this paper, a lensless imaging method is designed by diffuser 1-D moving, which decreases acquisition dada time, simplifies the experimental equipment and reduces experiment cost compared to typical ptychography based on 2-D shifting. A diffuser is placed into imaging system to improve resolution, which brought higher frequency information into the captured patterns via scattering effect. In field reconstruction, the additional amplitude constraint is added into the iterative phase retrieval algorithm. The proposed algorithm achieved faster convergence and reconstructed high-quality images. For the biological sample image, a wide field of view was realized with 20 diffraction patterns.