Single-mode optical fiber surface plasmon resonance sensor

Abstract A fiber optic surface plasmon resonance (SPR) sensor utilizing the resonant interaction between a guided mode of a single-mode optical fiber and a surface plasma wave supported by a thin metal film is described. Theoretical analysis of the SPR sensing structure based on the equivalent planar waveguide approach and the mode expansion and propagation method is presented. A detailed analysis of the effect of the major parameters of the SPR sensing structure on the sensor performance is carried out. Experimental results obtained with fabricated laboratory prototypes of the SPR sensing device for measurement of the refractive index of analyte are reported. It has been demonstrated that the fiber optic SPR sensing device may be used as a spectral as well as an amplitude sensor.