Surface Plasmon Resonance Sensor Based on an Angled Optical Fiber

Optical fiber-based surface plasmon resonance (SPR) sensors show great promise in applications for biochemistry detection. In this paper, a SPR sensor employing the angled optical fiber tip with a constant incident angle is reported. The incident angle and light interaction have been theoretical analyzed. The sensing probe has been fabricated via polishing the fiber tip to a specific angle. The process to achieve the smooth polished surface is also presented. The SPR spectra of solutions with different refractive indexes are obtained by collecting the light reflected by the angled fiber with metal coating. There is a red shift with the increase of analytes´ refractive index. Slightly different from the theoretical value 8300 nm/RIU, the sensitivity obtained in the experiment is 7650 nm/RIU.