Intelligent multiparameter sensing with fiber Bragg gratings

An approach to achieve intelligent sensing of multiple environmental parameters with a single-fiber sensor system is demonstrated through the use of multiplexed fiber Bragg gratings (FBGs) with coatings of different polymers and specifications. Using three FBGs of either acrylate or polyimide coating and polyimide coatings of different thicknesses, in situ discrimination of saccharinity, salinity, and temperature from the changes in the optical responses of the Bragg wavelengths of the gratings has been realized with sensitivities of 1.10×10−3 nm/%, 3.80×10−3 nm/% (blueshift), and 1.10×10−2 nm/°C (redshift), respectively.