Comparative Analysis of the Sensitivity of Optical Sensors Based on Surface Waves Excited in the Kretschmann Scheme

Abstract

Based on the theory of reflection of a limited light beam from a plane-layered structure, a surface plasmonic wave excited on the free surface of a gold film and, for comparison, a surface wave in a planar surface waveguide, both excited in the Kretschmann scheme, have been examined. The sensitivities of optical sensors based on these surface waves are compared. Various methods are proposed for increasing the sensitivity of sensors based on a surface waveguide. The required fabrication accuracy of film thicknesses to obtain workable sensors is estimated.