Coupled plasmon-waveguide resonance spectroscopic device and method for measuring film properties in the ultraviolet and infrared special ranges

摘要

A metallic (or semiconductor) layer (or layers) is used with either a prism or a grating so as to provide a surface plasmon wave under total reflection conditions of an incident light of predetermined wavelength outside the visible spectrum. The metal layer is selected with a refractive index as small as possible and an extinction coefficient as large as possible within the wavelength of interest and is covered with a solid dielectric layer characterized by predetermined optical parameters. This layer may contain one or several layers of different materials and plays the role of a light waveguide that generates waveguide modes coupled to surface plasmons, resulting in a new set of resonances excited by both p- and s-polarized excitation light and characterized by much narrower spectra than produced by conventional SPR. In a particular embodiment of the invention, the dielectric layer may be designed to serve both as a waveguide and at the same time as an electrode. This allows the combination of an optical device with an electrical device, capable of monitoring simultaneously electrical characteristics and optical parameters of thin films and interfaces.