Application of Centroid Principle to Wavelength Demodulation of Fiber Grating Sensors

Among the tunable filter technologies of optical fiber grating sensors, the peak method is an usual way, but it has poor precision and the result is unstable. A centroid principle method was proposed, which used the detection of wavelength variation by the centroid of scanned light intensity distribution curves. Compared with the peak method, the accuracy is improved 70 times and the error of the wavelength detection decreases greatly.