title: Refractive Index Sensing with D-Shaped Plastic Optical Fibers for Chemical and Biochemical Applications.
abstract: We report the optimization of the length of a D-shaped plastic optical fiber (POF) sensor for refractive index (RI) sensing from a numerical and experimental point of view. The sensing principle is based on total internal reflection (TIR). POFs with 1 mm in diameter were embedded in grooves, realized in planar supports with different lengths, and polished to remove the cladding and part of the core. All D-shaped POF sensors were tested using aqueous medium with different refractive indices (from 1.332 to 1.471) through intensity-based configuration. Results showed two different responses. Considering the refractive index (RI) range (1.33-1.39), the sensitivity and the resolution of the sensor were strongly dependent on the sensing region length. The highest sensitivity (resolution of 6.48 × 10-3refractive index units, RIU) was obtained with 6 cm sensing length. In the RI range (1.41-1.47), the length of the sensing region was not a critical aspect to obtain the best resolution. These results enable the application of this optical platform for chemical and biochemical evanescent field sensing. The sensor production procedure is very simple, fast, and low-cost.
authors.affiliation: Instituto de Telecomunicações, 3810-193 Aveiro, Portugal. fsequeira@av.it.pt.|CESAM, University of Aveiro, 3810-193 Aveiro, Portugal. fsequeira@av.it.pt.
authors.forename: Filipa
authors.initials: F
authors.lastname: Sequeira
authors.affiliation: Instituto de Telecomunicações, 3810-193 Aveiro, Portugal. dduarte@ua.pt.
authors.forename: Daniel
authors.initials: D
authors.lastname: Duarte
authors.affiliation: Instituto de Telecomunicações, 3810-193 Aveiro, Portugal. lucia.bilro@av.it.pt.|I3N/FSCOSD, Department of Physics, University of Aveiro, 3810-193 Aveiro, Portugal. lucia.bilro@av.it.pt.
authors.forename: Lúcia
authors.initials: L
authors.lastname: Bilro
authors.affiliation: CESAM, University of Aveiro, 3810-193 Aveiro, Portugal. alisa@ua.pt.|Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal. alisa@ua.pt.
authors.forename: Alisa
authors.initials: A
authors.lastname: Rudnitskaya
authors.affiliation: Department of Chemistry, University of Pavia, 27100 Pavia, Italy. maria.pesavento@unipv.it.
authors.forename: Maria
authors.initials: M
authors.lastname: Pesavento
authors.affiliation: Department of Industrial and Information Engineering, Second University of Naples, 81031 Aversa, Italy. zeni@unina.it.
authors.forename: Luigi
authors.initials: L
authors.lastname: Zeni
authors.affiliation: Department of Industrial and Information Engineering, Second University of Naples, 81031 Aversa, Italy. nunzio.cennamo@unina2.it.
authors.forename: Nunzio
authors.initials: N
authors.lastname: Cennamo
mesh_terms: D001671:Biochemistry / Q000379:methods*; D003198:Computer Simulation; D055100:Optical Fibers; D010969:Plastics / Q000737:chemistry*; D012031:Refractometry; D012815:Signal Processing, Computer-Assisted
chemical_list: D010969:Plastics
keywords: chemical and biochemical sensing; optical fiber sensors; plastic optical fiber (POF); refractive index sensors; remote sensing