Photon crystal waveguide-based surface plasmon resonance biosensor

The concept of a photonic crystal waveguide-based surface plasmon resonance sensor is proposed, in which plasmons on a surface of a thin metal film are excited by a Gaussian-like leaky mode of an effectively single mode photonic crystal waveguide. The authors demonstrate that effective refractive index of a waveguide core mode can be designed to be considerably smaller than that of a core material, enabling efficient phase matching with plasmons at any wavelength of choice, while retaining highly sensitive response to changes in the refractive index of an analyte layer. This is attractive for the development of portable surface plasmon resonance biochemical sensors.