More information thanks to additional dimension: angle and spectrally resolved scattered light measurements in VIS and NIR

With the goniometric setup developed at the ILM, the light scattered in a sample can be measured spectrally and angularly resolved in one plane. This can be used, for example, to determine the scattering phase function of single scatterers. For this purpose, based on simulations, a special cuvette was developed which avoids interfering reflections as far as possible and thus enables the direct measurement of the scattering phase function. The particles to be investigated are measured in suspension in this cuvette,

whose concentration must be low to avoid multiple scattered light. By means of the measured scattering phase function, for example, the diameter of the investigated particles can be determined very precisely (e.g. based on the Mie theory). The goniometer was verified using polystyrene and silica spheres of known diameter, confirming that even for samples with strong forward scattering, the scattering phase function can be determined without interference.