Plasmonic device for spectral analysis

The authors present an experimental demonstration of a fluidic-based plasmonic device for spectral analysis. The demonstrated device is based on the modification of surface plasmon resonance in periodically coupled metallic nanostructures using external refractive index perturbation for spectral analysis. The refractive index perturbation alters the resonance condition of the internal surface plasmon waves and introduces a spectral shift in the transmission band for spectral sampling. In this demonstration, precise control of the centre wavelength of the surface plasmon resonance was achieved by changing the local environment of the nanostructures via microfluidic channels. The fluidic-based approach has a great impact on existing resonance-based spectral analysis devices by offering an efficient way to acquire a very large number of spectral sampling.