SURFACE PLASMON RESONANCE DETECTOR WITH REPLACEABLE OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide an apparatus for measuring the refractive index of a substance using surface plasmon resonance in which matching is facilitated using a replaceable optical element. SOLUTION: The surface plasmon resonance detector comprises a substrate housing 12, and a detachable optical housing 19. Radiation from a radiation source 10 disposed in the substrate housing 12 is passed through a polarization filter to produce a polarized light which is then reflected on a plane mirror 20 to impinge on a surface plasmon resonance(SPR) layer 22 formed on the outer surface of the optical housing 19. The layer 22 comprises a thin layer of copper, silver or gold having uniform thickness which depends on the frequency of the radiation source 10 and the properties of material of the layer 22. Radiation 24 reflected on the layer 22 reinters into the housing 19 and impinges on an photoelectric detector array 28. Refractive index of a substance on the opposite side to the layer 22 is determined by the intensity and the angle of radiation at each detector.