<title>Polarization imaging through scattering media</title>

In recent years there has been an increasing interest in optical imaging through scattering media, including through body tissue, battlefield smoke, fog, rain, and mist, and muddy water. When an image is formed of an object embedded in a scattering medium, the image is comprised of the superposition of a sharp image plus a diffuse background. The light that propagates the shortest distance between the object and image plane forms the sharp image. The diffuse image is the result of the scattered light taking a random path between the object and image. In order to observe the sharp image formed by the weakly scattered light, the diffuse background must be removed from the image. Polarization based discrimination between weakly scattered and scattered light is based on the fact that weakly scattered light retains its incident polarization state whereas diffuse scattered light carries a random polarization state. In this paper, we will describe a polarimetric sensor and laboratory setup for imaging through scattering media. We will report the results from the laboratory measurements demonstrating imaging through several types of scattering media. Finally, we will discuss application of this technique to medical imaging, imaging through battlefield obscurants, and wireless communications.