Peak Detection of Fiber Bragg Grating Spectra Using Even-Odd Function for Spectral Decomposition

High precision uwCFBG wavelength calculation method based on correlation coefficient

“…To verify the validity of the novel algorithm, we analyze the accuracy of spectral barycenter results by using the parity function decomposition method and correlation coefficient solving method respectively. Ref [24] has proved that, as the relative position, the maximum value of the difference between them also changes constantly, so when the maximum value of the floating state is at the minimum, it corresponds to the position of the center of gravity of the spectrum. When there are multiple peaks, they need to be analyzed one by one.…”

“…1 [23]. Lu et al [24] used piecewise Gaussian function to represent asymmetric FBG, but uwCFBG have larger wavelength bandwidth of 3 dB and flatter wavelength region near the center. We assume that the wavelength pulses could be described by Gaussian signal, in this case, the spectral waveform function for uwCFBG can be expressed as:…”

“…In the field of fiber optic inertial navigation technology, the center wavelength of the spectrum is typically identified as the centroid of the broadband optical power spectral density [20]. Drawing inspiration from this, researchers employ the spectral odd-even function method to ascertain the maximum value, thereby identifying the center wavelength of the spectrum [21,22]. While this algorithm performs effectively on fiber Bragg grating (FBG) with a single peak, its application to uwCFBG with a relatively flat peak necessitates the computation of multiple sets of maximum values to determine the optimal value.…”