English: An incident beam of p-polarized light strikes an electrically conducting gold layer at the interface of a glass sensor with high RI (Refractive Index) and an external medium/sample with low RI. At a given angle, the excitation of surface plasmons takes place resulting in a reduced intensity of the reflected light, which can be seen as a dip in the SPR curve. In MP-SPR, the whole angular range is scanned automatically with multiple wavelengths providing information on molecular interaction kinetics and also on structure of the formed layer.