Polarization gated imaging in turbid media: a study with Monte Carlo simulation

Polarized light has been increasingly used in biomedical imaging to study the optical properties of biological tissues or enhance the imaging contrast by eliminating the scattered light. In this report, we combine polarization gating and Fourier gating to suppress interference by the diffusive photons and improve the quality of projection images. A Monte Carlo simulation is utilized to study the propagation of different polarized light through turbid media. Polarization of a photon is represented by a Stokes vector and the scattering matrix is calculated from Mie theory. By tracing the trajectory and the polarization of the photons, spatial distribution and polarization of photons transmitted through a spatial filter aperture are simulated. It is shown that polarization gating and Fourier gating can effectively reject the multiple scattered photons and improve the contrasts of the images. Differences between linearly and circularly polarized lights for scatterers of different size are compared. However, for large particles, effects of both gating techniques are limited.