@article{discovery1433922, note = {Copyright {\copyright} 2014 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.}, pages = {12634--12644}, journal = {Optics Express}, month = {May}, title = {Optimization of overlap uniformness for ptychography}, number = {10}, volume = {22}, year = {2014}, issn = {1094-4087}, author = {Huang, X and Yan, H and Harder, R and Hwu, Y and Robinson, IK and Chu, YS}, url = {http://dx.doi.org/10.1364/OE.22.012634}, abstract = {We demonstrate the advantages of imaging with ptychography scans that follow a Fermat spiral trajectory. This scan pattern provides a more uniform coverage and a higher overlap ratio with the same number of scan points over the same area than the presently used mesh and concentric [13] patterns. Under realistically imperfect measurement conditions, numerical simulations show that the quality of the reconstructed image is improved significantly with a Fermat spiral compared with a concentric scan pattern. The result is confirmed by the performance enhancement with experimental data, especially under low-overlap conditions. These results suggest that the Fermat spiral pattern increases the quality of the reconstructed image and tolerance to data with imperfections.} }