Ten implementations of ptychography

Summary Ptychography is an increasingly popular phase retrieval imaging technique, able to routinely deliver quantitative phase images with extended field of view at diffraction limited resolution. Different variants of this technique, like Bragg ptychography and Fourier ptychography, have also been developed and applied to various fields. Here we experimentally demonstrate 10 ways to implement the conventional real space transmission ptychography, and compare their properties to provide a guide to choosing the optimal setup for a specific application. Lay description Ptychography is a lensless imaging technique, able to routinely deliver quantitative phase images at diffraction limited resolution from a set of diffraction intensity measurements. There are three fundamental components: a confined coherent illumination, an overlapping scan strategy and an iterative image reconstruction algorithm. The confined illumination is scanned over the specimen at a grid of positions, such that the illuminated areas from two adjacent scan positions partially overlap (i.e. the overlapping scan). The transmitted (or reflected) wavefield is then captured by a camera located at somewhere downstream, but with the phase information of the wavefield lost. The overlapping scan generates redundancy in the measurements and the reconstruction algorithm allows us to utilise the redundancy to recover the phase information. Because no lens in involved during the whole imaging process, ptychography is...
Source: Journal of Microscopy - Category: Laboratory Medicine Authors: Tags: Original Article Source Type: research