Techniques to improve imaging through discrete scattering media

Imaging through random media is an important problem with many applications including optical remote sensing and bio-optics. In this paper, we will investigate the applications of Radiative Transfer Equation (RTE) in optical imaging. In particular, we study off-axis intensity subtraction (OAIS) and cross-polarization intensity subtraction (CPIS) imaging techniques. These techniques were proposed as a new way to improve image quality. We show the effectiveness of these techniques in this paper. Also, we investigate a new imaging technique using the freqency modulate waves, i.e., the photon density waves. We analyze the characteristic of intensity and polarization of the photon density waves with different modulation frequencies. We solve the RTE for linearly and circularly polarized waves by discrete ordinates method. Using the numerical solutions to the RTE, we will show the conditions in which OAIS and CPIS are most effective. Moreover, continuous photon density waves exhibit a narrow angular spectrum with a lower level of incoherent component compared to regular continuous waves. Also, the shape of pulse photon density waves shows less effect of multiple scattering of the random media. These findings establish the possibility of using photon density waves for better imaging.