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 mandate the measurement and analysis of singly-scattered light.  Multiple scattering in turbid or opaque samples strongly influences the outcome of the measurement and leads to results that can be wrong by orders of magnitude. As this can happen even with slightly turbid samples, artifacts are obtained quite frequently and remain often unnoticed. 

 
 
 

Multiple scattering result in an tubid or opaque appearance of the sample. Conventional dynamic or static light scattering can not be performed on such systems.

 
 
 

One powerful technique to suppress multiple scattering, known as 3D cross-correlation, uses

two simultaneous light scattering experiments performed at the same scattering vector on the

same sample volume in order to extract only the single scattering information common to both.

 
 

The correlation of the measured scattered intensities from both experiments with each other results in a cross correlation function where only single scattering events contribute to the signal.  Therefore the 3D cross correlation technique represents an extension of the classical techniques of  light scattering.

 

The 3D cross-correlation technology correlates the scattering signal from two experiments (2 beams) performed simultaneously at the same scattering angle.

 
 

3D cross-correlation further 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.  Such capabilities make it the most powerful and

versatile light scattering tool currently available. 

 
 
 

3D cross-correlation uses two laser beams that are focused on the sample at exact the same angle above and below the scattering plane. By cross-correlating the scattering signal multiple scattering can be suppressed efficiently in both dynamic and static light scattering.