Sensor fusion in ptychography

TL;DR

This paper introduces a novel sensor setup and an algorithm for ptychography that captures both low and high diffraction angles simultaneously, significantly enhancing image resolution through joint reconstruction.

Contribution

The work presents a new combined sensor configuration and an algorithm based on shifted angular spectrum and automatic differentiation for improved ptychographic imaging.

Findings

Enhanced resolution in ptychography through joint reconstruction.

Effective numerical aperture determined by off-axis sensor's maximum diffraction angle.

Significant improvement in resolving fine structures of the object.

Abstract

Ptychography is a lensless, computational imaging method that utilises diffraction patterns to determine the amplitude and phase of an object. In transmission ptychography, the diffraction patterns are recorded by a detector positioned along the optical axis downstream of the object. The light scattered at the highest diffraction angle carries information about the finest structures of the object. We present a setup to simultaneously capture a signal near the optical axis and a signal scattered at high diffraction angles. Moreover, we present an algorithm based on a shifted angular spectrum method and automatic differentiation that utilises this recorded signal. By jointly reconstructing the object from the resulting low and high diffraction angle images, the resolution of the reconstructed image is improved remarkably. The effective numerical aperture of the compound sensor is determined by the maximum diffraction angle captured by the off axis sensor.