A Simple Interrogator for FBG Sensors

A simple and portable interrogator for FBG sensors is reported. Reflected spectrum of FBG during strain measurement with broad band source is simulated, measured and compared. FBG is selected in such a way that the Bragg wavelength lies at the trailing edge of laser 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.