Open AccessTheoretical analysis of a fiber optic surface plasmon resonance sensor utilizing a Bragg grating
Author(s) -
Barbora Špačková,
Jiřı́ Homola
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.023254
Subject(s) - cladding (metalworking) , optics , materials science , fiber bragg grating , long period fiber grating , surface plasmon resonance , fiber optic sensor , coupled mode theory , refractive index , surface plasmon , cladding mode , optical fiber , localized surface plasmon , photonic crystal fiber , grating , mode volume , graded index fiber , plasmon , polarization maintaining optical fiber , optoelectronics , physics , nanoparticle , metallurgy , nanotechnology
A rigorous theoretical analysis of a fiber optic surface plasmon resonance sensor is presented. The sensor is based on the spectroscopy of mixed surface plasmon--fiber cladding modes excited by the fundamental mode of an optical fiber via a Bragg grating formed in the fiber core. The transmission spectrum is calculated by means of the Coupled Mode Theory. The modal structure is theoretically analyzed using a 3-D method based on a field expansion approach for matching the field continuity at the boundary of the layers. The theoretical analysis revealed a series of narrow transmission dips associated with the coupling of the fundamental mode to the mixed surface plasmon--fiber cladding modes. The sensitivity of these dips to changes in the refractive index of the analyte is calculated. Moreover, the refractive index resolution of the sensor was estimated to be better than 2 x 10(-6) RIU.