Optical Reflection Of As2se3-Au Plasmonic Planar Structure For Chemical Sensors Applications

Surface plasmon resonance in Kretschmann configuration is studied for a multilayer configuration containing an amorphous chalcogenide film of As2Se3. We investigated numerically and experimentally the resonance curve of a four-layers plasmonic sfructure. The As2Se3 film of the sfructure was deposited by vacuum thermal deposition over thin bare gold film. It was shown that for some amorphous film thicknesses the coupling between light beam and surface plasmon wave could be achieved by use of low refractive index prism like BK7 glass. The improved sensitivity of multilayers sfructure to small variations of the ambient refractive index as compared to the three layers Kretschmann configuration is highlighted.