Biomedical subjects
Publications and source records attributed to Erwan Baleine.
By adjusting the spatial coherence of a quasi-monochromatic beam, one can control the distance between two volumes of coherence. We propose to use such a beam in a typical scattering experiment and present a method for determining the degree of spatial correlation of a quasi-homogeneous medium by recording the scattered intensity in only one direction.
We propose a technique for determining the pair-correlation function of a quasi-homogeneous medium. The method uses the variation of the spatial-coherence properties of the incident beam to generate two separate volumes of coherence where the field is correlated. Using this specially prepared beam, we reconstruct experimentally the correlation function of a scattering potential by recording the scattered intensity in only one direction.
We describe a new imaging polarimeter that is based on a modified Sagnac interferometer and allows full polarimetric description of complex random electromagnetic beams from only two images as compared with the four images needed in conventional polarimetry. The procedure is analyzed in terms of the interference laws of Fresnel and Arago, and very good agreement with standard Stokes polarimetry is demonstrated. In certain cases the new technique provides the degree of polarization and the retardance from only one image.
When propagating through particulate media, optical beams are degraded owing to scattering. We found that the ratio between the width of the distorted beam and the width of the initial beam decreases when the spatial coherence of the incident beam is reduced. These experimental observations are well described within the paraxial approximation of the transport theory.