3D Cross-Correlation Light Scattering

 
 

A major drawback of conventional static and dynamic light scattering is its restriction to transparent samples, since these technologies both require the measurement and analysis of singly-scattered light only. Multiple scattering typical for turbid or opaque samples strongly influences the outcome of the measurement and leads to results that can be wrong by orders of magnitude. Because this can happen even with slightly turbid samples, artifacts are obtained quite frequently and often remain unnoticed. 3D cross-correlation is a powerful technique to suppress multiple scattering. This technique uses two simultaneous light scattering experiments performed at the same scattering vector on the same sample volume. In this manner the single scattering contribution will be identical in both experiments, but the multiple scattering contribution will be different!

The 3D cross-correlation technology correlates the scattering signal from two experiments (2 beams) performed simultaneously, laser

Laser beams for cross-correlation technology.

 

colloidal samples of different concentations, suspensions, colloids, turbid, transparent

With concentration, multiple scattering increases.

 

Related products:

 

Image presents LS Spectrometer which is an advanced instrument for DLS and SLS measurements. It enables measurement of hydrodynamic radius, radius of gyration, 2nd viral coefficient, molecular weight, form factor and structure factor.

3D LS Spectrometer

 

Image depicts NanoLab 3D which is suitable for DLS measurement of highly concentrated turbid samples

NanoLab 3D

 

The LSI Digital Correlator is perfectly suited for Dynamic Light Scattering

LSI Correlator

 

 
 

The correlation of both experiments with each other results in a cross-correlation function, which contains only the single scattering contribution. Therefore the 3D cross-correlation technique represents an extension of the classical techniques of  light scattering.

 
 

Schematic representation of 3D-cross correlation set-up,  spectrometer, light scattering

Schematical representation of the 3D-cross correlation set-up

 
 

The 3D cross-correlation technique also allows one to perform static light scattering experiments on strongly scattering samples by correcting the total measured scattered intensity by the angle-dependent single scattering contribution. The 3D LS Spectrometer is the only instrument that features the 3D cross-correlation technology in a goniometer setup thus allowing correction of dynamic and static light scattering at all scattering angles. This makes it the most powerful and versatile goniometer light scattering system currently available for DLS and SLS. 


The 3D cross-correlation technique can be further enhanced with the modulated 3D technique