Photonic and Plasmonic Waveguide Sensors

This paper reports on the conceptual design and simulation of a new hybrid coupled plasmon/dielectric waveguide device which may present opportunities for biosensing. The operation of the device is based on the phase matching of wave propagation in the dielectric waveguide with that of the surface plasmons. Finite element method (FEM) and eigenmode expansion (EME) methods have been utilised to analyse the characteristics of propagation of these waves. A suitable periodic grating structure has been implemented to provide wavelength dependent phase matching between the dielectric and plasmon modes. The selectivity of plasmon coupling makes it an ideal technology to be utilised for sensing. Such a device may be fabricated as a low cost, highly sensitive, integratable sensor allowing the detection of finite environmental changes including the presence of single layers of molecules.