WAVE-GUIDE SURFACE-PLASMON RESONANCE SENSORS

Planar waveguide surface plasmon resonance sensors have great potential for use in the field of environmental monitoring. In this paper we present a rigorous model for the optical power transmittance of this type of sensor. This model is used to determine the change in transmitted power when a thin layer is adsorbed to the metal-clad region of the sensor, as a function of the waveguide and metal film parameters. Design curves for sensors based upon glass waveguides coated with thin gold films immersed in water are presented. Experimentally determined changes in the output power of a waveguide surface plasmon sensor, as a function of the length of the gold film, are presented and compared to theory.