Optical sensor based on hybrid FBG/titanium dioxide coated LPFG for monitoring organic solvents in edible oils

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Coelho, L (Author) FCUP; Viegas, D (Author) FCUP; Santos, JL (Author) FCUP; de Almeida, JMMM (Author) FCUP

Journal

Title: Talanta

Vol. 148

Pages: 170-176

ISSN: 0039-9140

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 14 Citations

Scopus - 18 Citations

Other information

Authenticus ID: P-00G-T4V

DOI: 10.1016/j.talanta.2015.10.067

Abstract (EN): A hybrid optical sensing scheme based on a fiber Bragg grating (FBG) combined with a titanium dioxide coated long period fiber grating (LPFG) for monitoring organic solvents in high refractive index edible oils is reported. In order to investigate and optimize the sensor performance, two different FBG/LPFG interrogation systems were investigated. The readout of the sensor was implemented using either the wavelength shift of the LPFG resonance dip or the variation in the optical power level of the reflected/transmitted light at the FBG wavelength peak, which in turn depends on the wavelength position of the LPFG resonance. Hexane concentrations up to 20%V/V, corresponding to the refractive index range from 1.451 to 1.467, were considered. For the transmission mode of operation, sensitivities of 1.41 nm/%V/V and 0.11 dB/%V/V, with resolutions of 0.58%V/V and 0.29%V/V, were achieved when using the LPFG wavelength shift and the FBG transmitted optical power, respectively. For the FBG reflection mode of operation, a sensitivity of 0.07 dB/V/V and a resolution better than 0.16%V/V were estimated.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7