Fiber Bragg grating interrogator for temperature measurement

摘要

We report a novel FBG sensor based interrogator for temperature measurement. Reflected spectrum of FBG during temperature measurement with broad band source is simulated, measured and compared. Initially the performance of the proposed system is evaluated with a standard narrow band source and a power meter.FBG is selected in such a way that the Bragg wavelength lies at the trailing edge of narrow band source spectrum. The source spectrum is simulated and it is applied to the FBG. The simulated reflected power is found decreasing linearly with increase in strain. The actual reflected power is measured using a power meter and the results are compared. The proposed interrogator has a narrow band source with a FBG whose Bragg wavelength lies preferably in the trailing edge of the narrow band source spectrum. A photodiode connected to a current to voltage convertor forms the detector circuit.