Diffusing-wave spectroscopy
نویسنده
چکیده
Since its invention about a decade ago, dynamic multiple light scattering has found many applications in various areas of soft condensed matter science. It has become a particularly important quantitative to~1 in colloid physics because of its applicability to systems containing very high concentrations of scatterers, and its extreme sensitivity to small motions. Recent advances of this technique, currently called diffusing·wave spectroscopy because of the diffusive transport of the light waves, include remote optical measurements of frequencY'dependent viscoelasticity, studies of the microscopic dynamical processes in flowing sand and aging foam, a theoretical description of dynamic scattering from orientational fluctuations in liquid crystals and imaging of dynamic heterogeneities buried inside a turbid background medium.
منابع مشابه
Fast dynamics and relaxation of colloidal drops during the drying process using multispeckle diffusing wave spectroscopy.
The fast dynamics generated by the Brownian motion of particles in colloidal drops, and the related relaxation during drying, which play key roles in suspension systems, were investigated incorporating multispeckle diffusing wave spectroscopy (MSDWS). MSDWS equipment was implemented to analyze the relaxation properties of suspensions under a nonergodic and nonstationary drying process, which ca...
متن کاملTime-resolved diffusing wave spectroscopy applied to dynamic heterogeneity imaging.
We report what is to our knowledge the first observation of a time-resolved diffusing wave spectroscopy (DWS) signal recorded by transillumination through a thick turbid medium: the DWS signal is measured for a fixed photon transit time, which opens the possibility of improving the spatial resolution. This technique could find biomedical applications, especially in mammography.
متن کامل1 . 3 Diffusing - Wave Spectroscopy
This section focuses on recent work on temporal fluctuations of the intensity of multiply scattered light which are caused by motion of the scatterers. While parts ofthe underlying physics had already been discussed in 1983/84 [85, 86], dynamic multiple scattering of light was introduced by the work on calibrated colloidal latex particles in aqueous suspensions [29, 30, 87], and has since rapid...
متن کاملDiffusing-wave-spectroscopy measurements of viscoelasticity of complex fluids
We present a new use of dynamic light scattering that permits the determination of the viscoelastic behavior of a complex fluid. By describing the motion of a scattering particle in a viscoelastic medium in terms of a generalized Langevin equation with a memory function, we relate the time evolution of its mean-square displacement to the frequency-dependent storage and loss moduli of the medium...
متن کاملMicrorheology of polyethylene oxide using diffusing wave spectroscopy and single scattering.
Experiments investigating the local viscoelastic properties of a simple uncross-linked flexible polymer are performed on polyethylene oxide solutions in the semidilute regime using polystyrene beads of varying sizes and surface chemistry as probes. We measure the thermal motions of the beads to obtain the elastic and viscous moduli of our sample. Two different dynamic light scattering technique...
متن کاملAnalyzing the relationship between decorrelation time and tissue thickness in acute rat brain slices using multispeckle diffusing wave spectroscopy.
Novel techniques in the field of wavefront shaping have enabled light to be focused deep inside or through scattering media such as biological tissue. However, most of these demonstrations have been limited to thin, static samples since these techniques are very sensitive to changes in the arrangement of the scatterers within. As the samples of interest get thicker, the influence of the dynamic...
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