During the absorption, the particle or also the surrounding medium absorb a part of the electromagnetic energy of the impacting light.

This energy for the most part is converted into heat.

With dynamic light scattering (DLS) this can cause a warming of the medium and therefore lead to changes in the viscosity and mobility of the particles, with partly clear effects on the measuring results. Therefore is good temperature stabilization very important with DLS.

For the in static light scattering important Mie theory, plays the absorption (basically due to the particles) also a central part. In order to correctly describe the electromagnetic energy in a particle and therefore their effects on the angle dependent intensity distribution of the scattered light during particle sizing, is the knowledge of the absorption index of the particle material essential.