Faithful digital holographic reconstruction using a sparse sensor array

Abstract

The resolution and accuracy of the reconstruction are greatly limited by the field of hologram (FOH) in digital holography. Multi-apertures sampling in the hologram plane can achieve a large FOH. Sparse sensor aperture array uses the synthetic method to achieve higher spatial resolution than any single aperture, which can be used to a large-size scene imaging. However, accurate reconstruction is substantially degraded when there is a large gap between apertures. As a result, the entire scene could not be recovered from FOH. We present a self-restoration method that restores for gaps between sparse apertures. Constraints based on the object energy distribution and absorption characteristics are applied to extract the object function from existing defective reconstruction with a gap. The lost diffraction order can be reproduced and the original object function can be recovered by the iterations between object and hologram. Our iterative process allows a faithful recovery of the gap information to be extracted from the sub-holograms to achieve full-field imaging. The entire complex-value field that contains both the sampling and gap zones in the detection plane is finally retrieved. This faithful reconstruction using a sparse sensor array provides an effectively enlarged hologram for high-resolution digital holography.