Abstract: Surface plasmon resonance spectroscopy device includes an optical prism with a sample cell associated therewith and at least two sample detection areas that are provided with a thin metal coating selected for implementation of the SPR method and which contains, at least partially, surface-immobilized areas. Light is conducted via an optic fiber, collimated by a collimator with an aperture to a base surface of the prism, applied to an entrance of the optical prism. A multi adaptable diaphragm is provided between the collimator and the entrance surface. The diaphragm defines a path to the prism in a chronologically successive manner. Switching states are allocated to spectra corresponding to the switching states, whereby the spectra are obtained by detecting the light that leaves the prism through another collimator connected to another optic fiber applied to a polychromator wherein spectrally decomposed light is detected and evaluated by an evaluation and control unit.

Abstract: An optical sensor element for detecting organic compounds, particularly hydrocarbon. The sensor element permits the selective detection of substances by use of units which produce spectral displacements. This is realized by employing a spectral band filter, which comprises at least one layer of variable optical thickness of .lambda./4 and .lambda./2, respectively, or a multiple thereof, and said layer exhibits hydrophobic properties and includes organic affinity groups, the selection of which is adaptable to the substances to be detected.