title: Rapid high resolution imaging of diffusive properties in turbid media.
abstract: We propose a laser speckle based scheme that allows the analysis of local scattering properties of light diffusely reflected from turbid media. This turbid medium can be a soft material such as a colloidal or polymeric material but can also be biological tissue. The method provides a 2D map of the scattering properties of a complex, multiple scattering medium by recording a single image. We demonstrate that the measured speckle contrast can be directly related to the local transport mean free path l* or the reduced scattering coefficient μt = 1/l* of the medium. In comparison to some other approaches, the method does not require scanning (of a laser beam, detector or the sample itself) in order to generate a spatial map. It can conveniently be applied in a reflection geometry and provides a single characteristic value at any given position with an intrinsic resolution typically on the order of 5-50 μm. The actual resolution is however limited by the transport mean free path itself and can thus range from microns to millimeters.
authors.affiliation: Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, 1700 Fribourg, Switzerland. frank.scheffold@unifr.ch
authors.forename: Frank
authors.initials: F
authors.lastname: Scheffold
authors.forename: Ian D
authors.initials: ID
authors.lastname: Block
mesh_terms: D000465:Algorithms; D004058:Diffusion; D007834:Lasers; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D012996:Solutions / Q000737:chemistry*
chemical_list: D012996:Solutions