title: A refractive index sensor based on the resonant coupling to cladding modes in a fiber loop.
abstract: We report an easy-to-build, compact, and low-cost optical fiber refractive index sensor. It consists of a single fiber loop whose transmission spectra exhibit a series of notches produced by the resonant coupling between the fundamental mode and the cladding modes in a uniformly bent fiber. The wavelength of the notches, distributed in a wavelength span from 1,400 to 1,700 nm, can be tuned by adjusting the diameter of the fiber loop and are sensitive to refractive index changes of the external medium. Sensitivities of 170 and 800 nm per refractive index unit for water solutions and for the refractive index interval 1.40-1.442, respectively, are demonstrated. We estimate a long range resolution of 3 × 10(-4) and a short range resolution of 2 × 10(-5) for water solutions.
authors: Departamento de Física Aplicada, Instituto de Ciencia de los Materiales, Universidad de Valencia, Burjassot 46100, Spain. Mauricio.Reyes@uv.es
authors: Mauricio
authors: M
authors: Reyes
authors: David
authors: D
authors: Monzón-Hernández
authors: Alejandro
authors: A
authors: Martínez-Ríos
authors: Enrique
authors: E
authors: Silvestre
authors: Antonio
authors: A
authors: Díez
authors: José Luis
authors: JL
authors: Cruz
authors: Miguel V
authors: MV
authors: Andrés
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D012996:Solutions / Q000737:chemistry*; D014159:Transducers
chemical_list: D012996:Solutions
references: Opt Lett. 2011 Jun 15;36(12):2197-9
references: 21685965
references: Opt Lett. 2005 Mar 1;30(5):453-5
references: 15789700
references: Opt Express. 2005 Jun 13;13(12):4476-84
references: 19495362
references: Appl Opt. 1982 Dec 1;21(23):4208-13
references: 20401043
references: Opt Lett. 2007 Aug 15;32(16):2390-2
references: 17700795
references: Opt Lett. 1996 May 1;21(9):692-4
references: 19876127
references: Opt Express. 2008 Jan 21;16(2):1062-7
references: 18542179
references: Appl Opt. 1980 Aug 1;19(15):2606-11
references: 20234469
references: Opt Lett. 2010 Feb 15;35(4):613-5
references: 20160835
references: Appl Opt. 2009 Nov 1;48(31):6044-9
references: 19881672
references: Opt Lett. 2012 Jun 1;37(11):1974-6
references: 22660092