title: Information multiplexing in ptychography.
abstract: We show for the first time that ptychography (a form of lensless diffractive imaging) can recover the spectral response of an object through simultaneous reconstruction of multiple images that represent the object's response to a particular mode present in the illumination. We solve the phase problem for each mode independently, even though the intensity arriving at every detector pixel is an incoherent superposition of several uncorrelated diffracted waves. Until recently, the addition of incoherent modes has been seen as a nuisance in diffractive imaging: here we show that not only can the difficulties they pose be removed, but that they can also be used to discover much more information about the object. If the illumination function is also mode-specific, we show that we can also solve simultaneously for a multiplicity of such illumination modes. The work opens exciting possibilities for information multiplexing in ptychography over all visible, X-ray and electron wavelengths.
authors.affiliation: Department of Electrical and Electronic Engineering, University of Sheffield, S1 3JD Sheffield, UK.
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Batey
authors.affiliation: Department of Electrical and Electronic Engineering, University of Sheffield, S1 3JD Sheffield, UK. Electronic address: claus@ito.uni-stuttgart.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Claus
authors.affiliation: Department of Electrical and Electronic Engineering, University of Sheffield, S1 3JD Sheffield, UK; Research Complex at Harwell Rutherford Appleton Laboratory, Harwell Oxford, Didcot Oxon OX11 0FA, UK.
authors.forename: John M
authors.initials: JM
authors.lastname: Rodenburg
keywords: Biomedical imaging; Coherent diffractive imaging; Information multiplexing; Optical metrology; Ptychography