Resolution-enhanced ptychography framework with an equivalent upsampling and precise position

Abstract

As a lensless imaging technique, ptychography provides a new way to resolve the conflict between the spatial resolution and the field of view. However, due to the pixel size limit of the sensor, a compromise has to be reached between the spatial resolution and the signal-to-noise ratio. Here, we propose a resolution-enhanced ptychography framework with equivalent upsampling and subpixel accuracy in position to further improve the resolution of ptychography. According to the theory of pixel superresolved techniques, the inherent shift illumination scheme in ptychography can additionally enhance the resolution with the redundant data. An additional layer of pooling is used to simulate the downsampling of a digital record, and the pixel superresolved problem is transformed into an automatic optimization problem. The proposed framework is verified by optical experiments, both in biological samples and the resolution targets. Compared to the traditional algorithm, the spatial lateral resolution is twice as large using the same data set.