Surface Plasmon Resonance Sensor in Plastic Optical Fibers. Influence of the Mechanical Support Geometry on the Performances

A performance analysis on Surface Plasmon Resonance (SPR) sensor based on D-shaped Plastic Optical Fibers (POFs) is reported. It is a very low cost sensor for determining refractive index variations at the interface between a metallic layer and a dielectric medium. This POF-SPR optical platform can be used in many bio and chemical applications. The advantage of using POFs is that the sensor platforms based on POF are simpler to manufacture than those made using silica optical fibers. For low-cost sensing systems, POFs are especially advantageous due to their excellent flexibility, easy manipulation, great numerical aperture, large diameter, and the fact that plastic is able to withstand smaller bend radii than glass. In this work the authors investigate the role of the geometric shape of the resin block, used to obtain a D-shaped POF. In fact, different resin blocks can produce different performances. Two different POF-SPR sensors, based on two different geometric shapes of the resin block, with numerical and experimental results, are presented.