Patent ID: 7701582

Claim:
A method for carrying out surface plasmon resonance measurement, in which method a beam of electromagnetic radiation is produced by a source of electromagnetic radiation, the beam of electromagnetic radiation is directed through a prism onto a material layer in an angle of incidence, which material layer at least partly covers a planar surface of the prism, a surface plasmon resonance phenomenon is caused, a beam of reflected electromagnetic radiation is produced and directed by the surface through the prism and further to a detector for detecting the level of intensity of the beam of reflected electromagnetic radiation, the change of the level of intensity of the beam of reflected electromagnetic radiation, caused by the surface resonance phenomenon, is measured, and the beam of reflected electromagnetic radiation being reflected with a mirror to the detector, wherein the angle of incidence is varied to cause the surface plasmon resonance phenomenon by at least one of: i) rotating the prism and the mirror together with respect to the source of electromagnetic radiation and the detector, and ii) rotating the source of electromagnetic radiation and the detector together with respect to the prism and the mirror, wherein the rotating of the prism and the mirror together with respect to the source of electromagnetic radiation and the detector comprises rotating the prism and the mirror each to a same first angle, so as to cause the surface plasmon resonance phenomenon, and wherein the rotating of the source of electromagnetic radiation and the detector together with respect to the prism and the mirror comprises rotating the source and the detector each to a same second angle, so as to cause the surface plasmon resonance phenomenon.