Ptychographic imaging of incoherently illuminated extended objects using speckle correlations

Appl Opt. 2019 May 1;58(13):3564-3569. doi: 10.1364/AO.58.003564.

Abstract

A scattering layer is usually considered an obstacle to imaging. However, using speckle correlation imaging techniques, the scattering layer effectively acts as a lens. To date, the speckle correlation imaging method has been limited to imaging sparse samples. Here, we demonstrate imaging of incoherently illuminated extended objects in transmission and around-the-corner geometries. We are able to image extended objects by constraining the illumination spot on the object and then scanning the object. A ptychography algorithm is used to reconstruct the extended object. This work demonstrates the applicability of ptychography to spatially incoherent light and enables a new method of imaging in spectral regions where there is limited choice in optics, such as the terahertz, extreme ultraviolet, and x-ray regions.