Approaching the limits of multiple scattering decorrelation: 3D light-scattering apparatus utilising semiconductor lasers

Characterization of Turbid Colloidal Suspensions Using Light Scattering Techniques Combined with Cross-Correlation Methods

“…2B, the intercept of the auto-correlation function has decreased considerably, we observe strong distortions at short lag times , and the characteristic decay times are much smaller now. While the decrease in intercept is mainly caused by the fact that the coherence length of the laser is shorter than the average photon path length in the sample, 2 the shift of the characteristic correlation times measured in an auto-correlation experiment is a genuine effect of multiple scattering (7,8). This, for example, severely limits the ability to recover the correct distribution of diffusion coefficients or particle hydrodynamic radii in particle-sizing experiments with large particles such as emulsion droplets to low concentrations only.…”

Structure, Dynamics, and Optical Properties of Concentrated Milk Suspensions: An Analogy to Hard-Sphere Liquids

“…This strong scattering arises, in particular, from the casein micelles and the fat globules. Recently, a novel approach that suppresses contributions from multiple scattering was developed (18)(19)(20)(21)(22). The basic principle of this new instrument is to perform two simultaneous light-scattering experiments with the same scattering vector q in exactly the same scattering volume.…”

Correlation functions of singly and multiply scattered light analysed by the 3-D cross-correlation technique

“…Applying such methods, the properties of singly scattered light can be measured in rather turbid samples. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The basic idea of the two-beam cross-correlation methods 6 is to perform simultaneously two scattering experiments:…”

“…The cross-correlation function turns out to be equivalent to the single scattering auto-correlation function. In the three dimensional (3-D) coding technique, [10][11][12][13][14][15][16][17][18][19][20] applied in this work, two scattering planes are considered, which are tilted to each other in such a way, that the conditions (a) and (b) are satisfied. A coding technique using two different wavelengths (two-colour coding) was developed before and successfully applied.…”