3D-PSTD applied to the resolution in time and space of the time reversal of an image transmitted through a scattering medium

In this paper we present a three dimensional numerical model, based on a Pseudo-Spectral Time Domain algorithm (PSTD), that simulates the propagation of light carrying an image through a scattering medium and the back propagation of the scattered light which is reflected back by a phase conjugate mirror, modelled thanks to the nonlinear optical process of three-wave-mixing. We show how the phase conjugate wave retraces the scattering path and retrieves the spatial information of the input image with a signal to noise ratio that depends on the lateral dimensions of the phase conjugate mirror and of the number of realizations cumulated. Moreover, we show that the image restoration is not precluded by the polarization change between the phase conjugate wave and the scattered light exiting the complex medium.