SPR fiber based sensor for long-term monitoring of aqueous media

The paper presents results obtained by experimentally testing fiber optic based SPR (Surface Plasmon Resonance) sensors for quality monitoring of aqueous media. The research focuses on the direct impact of the temperature in such measurements for certain applications, being introduced as a parasitic effect. A novel and cost effective configuration for a fiber optic based SPR sensor system, exploiting a compensation method of the thermo-optic effect, is also presented. Its working principle is already proven based on previous results and performances obtained from experimental work, and it is ready to be implemented. The sensor is basically a refracto-meter in the range of 1.33-1.37 RI (Refractive index), thus for aqueous media, intended to be used as a long-term monitoring device for the quality of the swimming pool water (real time chlorine concentration analysis) compensating the parasitic effect of temperature.