Fiber Bragg grating based surface plasmon resonance sensor utilizing FDTD for alcohol detection applications

A fiber Bragg grating (FBG) based surface plasmon resonance (SPR) sensor is investigated using 2-D finite difference time domain (FDTD) simulation. The sensitivity and accuracy of the sensor with and without gratings is observed as well as the effect of changing the grating distance on the resonant wavelength. The findings show that high sensitivity of above 500nm/RIU and a fourfold increase in signal to noise ratio (SNR) is obtained by introducing FBG to the basic fiber optic based SPR structure. Increasing the grating period results in a red shift in the resonant wavelength, thus enabling multiple sensor fabrication on a single fiber optic cable. Simulation of the FBG based SPR sensor to detect alcohol concentration from 0 to 100% in water is also demonstrated

Fiber Bragg grating sensor for detecting ageing transformer oil

In this paper, we report the investigation of monitoring the degradation of transformer oil in power transformer using fiber Bragg grating sensor (FBG). The findings show that aging transformer oil has a higher refractive index (RI) compared to fresh transformer oil. This is detected by a wavelength shift in the FBG sensor's spectral response. The outcome complies with the breakdown voltage test which is the standard test for testing transformer oil ageing. Finally, we show that the sensor is temperature independent