title: Sensitive liquid refractive index sensors using tapered optical fiber tips.
abstract: An optical fiber sensor based on the change of optical confinement in a subwavelength tip is presented. The optical spot is substantially increased when the environmental refractive index (RI) increases from 1.3 to 1.4. By measuring the intensity of low angular spectral components, an intensity sensitivity up to 8000% per RI unit is achieved. The fiber tip sensors take advantage of the small detection volume and real-time responses. We demonstrate the application of the nanofiber sensors for measuring concentrations of acids and evaporation rates of aqueous mixtures.
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Yi-Hsin
authors.initials: YH
authors.lastname: Tai
authors.forename: Pei-Kuen
authors.initials: PK
authors.lastname: Wei
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions / Q000737:chemistry*; D014159:Transducers
chemical_list: D012996:Solutions