OPTICAL-FIBER SENSOR-BASED ON SURFACE-PLASMON EXCITATION

A very sensitive sensor structure for measurement of small changes of the refractive index employing the interaction between the surface plasmon and the guided mode of a single-mode optical fiber is reported. The theoretical treatment of the proposed sensor structure based on planar waveguide approximation is presented. The analysis of the influence of the main parameters of the sensor structure on the sensor performance is carried out with the aim of finding an optimum strategy for designing optical sensors with high sensitivity. The possibility of connecting the sensor to a broadband light source is also discussed.