Non-invasive depth-resolved imaging through scattering layers via speckle correlations and parallax

Abstract

Various approaches for imaging through scattering layers have been proposed, but very few of them provide depth-resolved images. Here, we propose and experimentally demonstrate an approach for non-invasive depth-resolved imaging of objects hidden behind a scattering medium based on speckle correlations and parallax. The relative intensities of the objects' autocorrelations and the positions of the cross-correlations, both change from different apertures. The reconstruction of objects is achieved by subtraction of the autocorrelations and the conventional Fienup-type iterative phase-retrieval algorithm, and the objects' relative position is retrieved from the relative position of the cross-correlation to the central; moreover, the depth information of objects is decoded by the displacement of the cross-correlations through different apertures. This multi-aperture technique allows sharp imaging of objects with full actual depth information at once.