Coherent imaging of objects through thin-layer highly scattering medium based on optical encryption

Abstract

In this paper, we declare that the scattering system of coherence light passing through a thin-layer highly scattering medium can be treated as a 4f system of single random phase encoding (SRPE). Assuming no energy loss, the target image behind a thin-layer highly scattering medium can be recovered by using an attack method in a SRPE-4f encryption system. The idea originates from the analysis of speckle field and theoretical model of the system. On the one hand, the statistical distribution of the speckle in the scattering system is consistent with that of the cyphertext in the corresponding SRPE-4f encryption system, which provides the base for equivalent replacement. On the other hand, the point spread function of a thin-layer highly scattering medium is equivalent to the Fourier transform of random phase mask of the SRPE-4f system, which can be used for key estimation in scattering imaging. Both the theory analysis and results of the experiment verify the validity and feasibility of our proposed, and we believe this contribution will open up a novel way to deepen the research of imaging through scattering medium.