Localized surface plasmon resonance based fiber optic sensor with nanoparticles

Abstract

A localized surface plasmon resonance (LSPR) based fiber optic sensor with a nanoparticle layer coated on the core of the optical fiber has been presented and theoretically analyzed. Nanoparticles of four materials: ITO, Au, Ag and Cu have been considered for the study. The complete analysis of sensitivity of the LSPR based fiber optic sensor with each nanoparticle layer individually for various values of thickness and particle size has been done numerically in order to use these four materials in plasmonic sensing applications. The sensitivity of LSPR based fiber optic sensor increases with the increase in the thickness of nanoparticles layer for all four materials. Also, for a fixed value of thickness of nanoparticles layer, the sensitivity of LSPR based fiber optic sensor further increases as the particle size of nanoparticles increases (up to 20nm). The optimized values of thickness and particle size of nanoparticles layers for all four materials individually are revealed to be 60nm and 20nm respectively. With sensitivity of 6240nm/RIU, the 60nm thick ITO nanoparticles layer (with 20nm particle size) based LSPR sensor has been shown to have better performance than other three material's naoparticles based LSPR sensors.