Double-blind digital in-line holography from multiple near-field intensities

We present a phase retrieval technique for the recovery of complex-valued wave-fields from multiple near-field diffraction measurements. The proposed method does neither rely on any a priori knowledge about the sample nor on knowledge about an external reference wave, but instead uses multiple self-referencing object exit surface waves that are iteratively recovered. The key ingredient to our approach is a system of relaxed coupled waves that allow for the incorporation of holographic data. We use diffraction measurements of multiple exit surface waves as well as their holograms at multiple sample-detector distances to provide sufficient data redundancy to successfully reconstruct the complex-valued wave field. Parameters for stable performance are investigated. Numerical reconstruction is shown by simulation and experiment to be robust against systematic errors such as position uncertainty and noise. The method proposed is realizable at low cost with instrumentation available in typical optical laboratories.