Optimized synthesis of fiber Bragg gratings with triangular spectrum for wavelength-interrogation application

A novel method for synthesizing arbitrary-shape triangular-spectrum fiber Bragg gratings (TS-FBGs) is proposed. It involves the use of a discrete layer peeling method for exploiting initial guess and a simulated annealing method for optimizing the desired grating parameter. By comparing it to the reported TS-FBGs synthesis methods, the proposed method has advantages of reducing the maximum index modulation and smoothing index modulation profile simultaneously. We employ the proposed method to synthesize FBGs with symmetric, asymmetric, and right-angled triangular spectrum, all of which have the low and smooth index modulation profiles. The synthesized gratings can act simple and cost-effective wavelength-interrogation devices in optical sensor systems