Diffusing-wave interferometry

High-Dilution Diffusion of K, Rb , Cs, and Tl in the Molten System (Li-K)NOs Studied by Wave-Front-Shearing Interferometry

The high-dilution diffusion coefficients of K+, Rb+ , Cs+, and T1+ in molten LiN03—KN03 mixtures are measured over a wide range of temperatures and concentrations by means of wavefront-shearing interferometry. A slightly positive deviation from linearity is found for the concentration dependence of the diffusion coefficient of K + , Rb+ , and T1+, while no deviation is found for Cs+ within the ...

Accounting for inertia effects to access the high-frequency microrheology of viscoelastic fluids.

We study the Brownian motion of microbeads immersed in water and in a viscoelastic wormlike micelles solution by optical trapping interferometry and diffusing wave spectroscopy. Through the mean-square displacement obtained from both techniques, we deduce the mechanical properties of the fluids at high frequencies by explicitly accounting for inertia effects of the particle and the surrounding ...

Path-length-resolved dynamic light scattering in highly scattering random media: The transition to diffusing wave spectroscopy

We used low coherence interferometry to measure Brownian motion within highly scattering random media. A coherence gate was applied to resolve the optical path-length distribution and to separate ballistic from diffusive light. Our experimental analysis provides details on the transition from single scattering to light diffusion and its dependence on the system parameters. We found that the tra...

Time-lapse travel time change of multiply scattered acoustic waves

Existing techniques in correlation spectroscopy, such as coda wave interferometry and diffusing acoustic wave spectroscopy, determine the average motion of scatterers or change in the propagation velocity from the temporal change of multiply scattered sound. However, neither of them gives an indication of the spatial extent of the change in the medium. This study is an extension of the techniqu...

Attosecond electron wave packet interferometry