title: Influence of size parameter and refractive index of the scatterer on polarization-gated optical imaging through turbid media.
abstract: The influence of incident polarized light, refractive index, and size parameter of the scatterer on achievable resolution and contrast (image quality) of polarization-gated transillumination imaging in turbid media is reported here. Differential polarization detection led to significant improvement of image quality of an object embedded in a medium of small-sized scatterers (diameter D<<lambda, isotropic scattering medium, anisotropy parameter g<or=0.2), especially using circular polarization. In contrast, for anisotropic scattering media composed of larger-sized scatterers (D>or=lambda,g>or=0.7), the improvement in image quality was less pronounced using either linear or circular polarization gating when the refractive index of the scatterer was high (ns=1.59), but for a lower value of refractive index (ns=1.37), image quality improved with the differential circular polarization gating. We offer a plausible explanation for these observations.
authors.affiliation: Department of Physics and Center for Laser Technology, Indian Institute of Technology Kanpur, India.
authors.forename: Prashant
authors.initials: P
authors.lastname: Shukla
authors.forename: R
authors.initials: R
authors.lastname: Sumathi
authors.forename: Sharad
authors.initials: S
authors.lastname: Gupta
authors.forename: Asima
authors.initials: A
authors.lastname: Pradhan
mesh_terms: D003952:Diagnostic Imaging; D007089:Image Enhancement / Q000379:methods*; D008027:Light; D055095:Optics and Photonics; D012031:Refractometry; D012542:Scattering, Radiation