Sensitivity measurement of fibre bragg grating system for temperature sensor application

A practical pass-through type fibre Bragg grating (FBG) temperature sensor system have been designed and experimentally investigated. The performance of FBG was evaluated with the varying of focusing elements in harsh environments. The sensor head of FBG was designed to be focussed with a convex lens and hand lens as well as without any focusing element. The systems' temperature was measured using a mercury thermometer placed near to the FBG sensor head. The broadband laser source was launched in the system using tunable laser source (TLS) while the transmission and reflection spectra of the FBG were measured by an optical spectrum analyser (OSA). The results shows that the Bragg wavelength shift, ΔλBincrease proportionally with the temperature. The sensitivity of the FBG was recorded to be 0.0100 and 0.0132 nm ° C-1for the systems where convex and hand lens applied to the FBG's sensor head respectively, while the sensitivity of 0.0118 nm ° C-1measured for the system without any focussing element applied. © 2015 American Scientific Publishers.