Scattering of diffused photon pair density wave by a spherical or by a cylindrical inhomogeneity in a multiple scattering medium

We study the scattering of diffused photon pair density wave (DPPDW) from a spherical and cylindrical inhomogeneity embedded in a homogeneous multiple scattering medium. In this study, DPPDW is composed of correlated polarized photon pairs at different temporal frequencies and parallel linear polarized states in a multiple scattering medium where two linear polarized photons are common-path propagating in the scattering medium. The heterodyne signal is then generated by a photomultiplier tube. By measuring the amplitude attenuation and the phase delay of heterodyne signal at different position of the scattering medium, the diffracted amplitude and phase wavefront of DPPDW are obtained precisely and simultaneously. In this experiment, the distorted phase wavefront and amplitude wavefront by a perfect spherical or cylindrical absorber in a multiple scattering medium is investigated. Because the feature of common-path propagation of polarized pair photons in a multiple scattering medium and the polarization gating and the spatial coherence gating working simultaneously, the sensitivity of the amplitude and phase detection of DPPDW are then enhanced significantly. The ability of detecting a smaller size of optical inhomogeneity in a multiple scattering medium is discussed and the experimental results consistent with the theoretical expectation are demonstrated.